User Guide

Glossary 321
IFO file One of the files on a DVD-Video disc. The IFO file contains instructions that tell the
DVD player how to play the VOB files on the disc. Because the disc could become
unplayable if the IFO file is damaged, a backup copy with the extension .BUP is always
included in a separate location on the disc.
interleaved scanning Method for displaying an analog video signal on a television screen.
This method was developed because video images flicker when displayed on televisions at
25 or 29.97 frames per second — each frame fades away before the next one appears.
To prevent flickering, each video frame is divided into two fields. One field contains all the
odd-numbered scan lines in the frame (the “top” field); the other contains all the even-
numbered scan lines (the “bottom” field). The television displays one field (one set of lines),
followed by the next, at 59.94 fields per second for NTSC or 50 fields per second for PAL. At
these frequencies, human persistence of vision causes the fields to be perceived as a single
image.
Compare with progressive scanning.
ISO 9660 Specifies the naming convention for computer file names. Level 1 limits filenames
to eight characters plus a three-character extension using uppercase A to Z, digits 0 to 9 and
the underscore “_” character; known as the “8.3” or MS-DOS format. Level 2 allows names
up to thirty characters, using all ASCII characters.
IYUV See I420.
Joliet Extension to the ISO 9660 file system that allows long file names, and file names with
spaces and international characters. to long file names. Available with Windows 95 (or later)
and Windows NT.
JPEG Lossy compressed bitmap graphics format developed by the Joint Photographic
Experts Group. Files have the extension .jpg or .jpeg.
k Standard abbreviation for kilo (thousand). Used as a prefix in units of measurement such
as kbps (kilobits per second) and kHz (kilohertz).
K Standard abbreviation for 1,024 (2
10
). Used as a prefix in measurements of computer
bytes.
KB (Kilobyte) 1,024 (2
10
) bytes.