True HD

This has no strict technical meaning but is marketing hype. The ATSC says that all HD, 720P, 1080I and 1080P are all true HD, but the term has tended to be associated with 1080P often in advertising – but this is nothing official. Not to be confused with... TrueHD.

TrueHD Dolby’s ‘next-generation’ lossless technology developed for high-definition disk-based media (HD DVD and Blu-ray Disc). It includes ‘bit-for-bit’ lossless coding up to 18 Mb/s and support for up to eight channels of 24-bit, 96 kHz audio. It is supported by HDMI. Website: www.dolby.com

TrueType (fonts) The TrueType vector font format was originally developed by Apple Computer, Inc. The specification was later released to Microsoft. TrueType fonts are therefore supported on most operating systems. Most major type libraries are available in TrueType format. There are also many type design tools available to develop custom TrueType fonts.

Truncation

Removal of the least significant bits (LSBs) of a digital word – as could be necessary when connecting 10-bit video equipment into 8-bit video equipment, or handling the 16-bit result of digital video mixing on an 8-bit system. If not carefully handled truncation can lead to unpleasant artifacts on video signals – such as contouring. See also: Dynamic Rounding

UHD

Ultra HD developed by NHK Labs has a format of 7680x4320 (16 times the area of 1920 x 1080 HD) at 60 f/s and with 22.2 audio. This remains a lab project with possible consumer product as far away as 20 years. Presentations at big trade shows (NAB, IBC) have been impressive.

Uncommitted editing Editing where the decisions are made and the edits completed but any can still easily be changed. This is possible in an edit suite that includes true random access editing – where the edits need only comprise the original footage and the edit instructions. Nothing is re-recorded so nothing is committed. This way, decisions about any aspect of the edit can be changed at any point during the session, regardless of where the changes are required. Where new frames are generated, such as in mixes, dissolves and compositing, all the tools and their settings are available – preferably on the edit timeline. See also: True random access.

Unicode Unicode allows computers to consistently represent and manipulate text in most of the world’s writing systems – 30 are currently implemented – describing about 100,000 characters. The Unicode Standard is widely adopted and supported by the computer industry Website: www.unicode. org

Up-res

The process which increases the size, or number of pixels used to represent an image by interpolating between existing pixels to create the same image on a larger format. There is no implied change of vertical scan rate. Despite its name, the process does not increase the resolution of the image; it just spreads the same over a larger canvas. The quality of the result depends on that of the interpolation. Speed is an issue for realtime

work, as good quality requires a large amount of processing – which increases with the picture area. See also: Down-res, Format conversion

USB

Universal Serial Bus – now available as USB 2.0 which, with 480 Mb/s maximum transfer rate, offers potentially useful connectivity for media applications on PCs and Macs. It is very cheap and widely used for connecting PC peripherals. It is a PAN, and so the service provided to any one device depends on their specification and on what other connected devices are doing. Actual speeds achieved for bulk data transfers are about 300 Mb/s – but this is likely to rise. See also: IEEE 1394 V

Vaporware

Software or hardware that is promised or talked about but is not yet completed – and may never be released. See also: RSN

Variable bit rate (VBR) compression

While many video compression schemes are ‘constant bit rate’ – designed to produce fixed data rates irrespective of the complexity of the picture, VBR offers the possibility of fixing a constant picture quality by varying the bit-rate according to the needs of the picture. This allows the images that require little data, like still frames in MPEG-2, to use little data and to use more for those that need it, to maintain quality. The result is an overall saving in storage, as on DVDs, better overall quality, or more efficient allocation of total available bit-rate in a multi-channel broadcast multiplex. See also: Constant bit rate, DVD, Statistical multiplexing

Varicam

Panasonic camcorder based on DVCPRO HD that was the first to offer variable frame rates from 4to 60Hz at1280 x 720P. So, if working at a nominal 24 fps, the system offers x 6 speed up (undercranking) to x 2.5 slow down (overcranking). The system works by continuously recording 60 f/s to tape while the images are captured at the appropriate rate. Then the relevant useful frames are flagged. See also: VFR V VC-1 VC-1 is a video codec specification (SMPTE 421M-2006) and implemented by Microsoft as Windows Media Video (WMV) 9, and specified in HD DVD and Blu-ray Disc, and many others. It is designed to achieve state-of-the- art compressed video quality at bit rates ranging from very low to very high with low computational complexity for it to run well on PC platforms. Individual opinions differ but broadly speaking VC-1 offers at least similar performance and efficiency to H.264/AVC – some say it looks better. VC-1 offers a number of profiles for coding features, and levels of quality combinations defining maximum bit rates. These have a wide range from 176 x 144/15P which may be used for mobile phones, to 2K (2048 x 1536/24P) for movie production.

VC-2 See also: Dirac

VC-3 Avid’s DNxHD codec currently undergoing standardization by SMPTE may be given this designation. See also: DNxHD

Vector fonts

Fonts that are stored as vector information – sets of lengths and angles to describe each character. This offers the benefits of using relatively little storage and the type can be cleanly displayed at virtually any size.

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GLOSSARY OF TERMS