User Guide

Glossary 317
DDP (Disc Descriptor Protocol) Report that provides information about the disc that will be
created from the DVD master. Product Name writes a DDP report onto the master along
with the DVD data.
decode To process digital data to reconstruct the original (analog) source.
digital Represented by discrete numbers (digits). In general, digital is synonymous with
binary because computers store and process information coded as combinations of binary
digits (bits). Compare with analog.
DirectShow Software standard developed by Microsoft Corporation for playing digital video
and audio on Windows-based PCs.
DLT (Digital Linear Tape) Standard tape format required by disc replicators.
DMA (Direct Memory Access) Method for transferring data directly to a device such as a
hard disk without using the CPU. This greatly speeds up applications that need to write large
amounts of data to the device.
Dolby Digital (AC-3) Audio codec, developed by Dolby Laboratories, that uses perceptual
coding to deliver low-bandwidth audio. Dolby Digital is supported by all DVD players. Dolby
Digital bit rates for DVDs ranges from 192 kbps for mono and stereo to 384–448 kbps for
5.1 surround sound.
drop frame, non-drop frame NTSC-format video can contain either drop-frame timecode or
non-drop-frame timecode.
The NTSC frame rate is 29.97 fps. Timecode counters cannot count anything less than a
whole frame, so NTSC timecode counters increment the second count after every 30
frames; therefore, one second on the timecode counter is slightly longer than a real second
(0.03 frames, or about one-thousandth of a second longer). This does not sound like much,
but over time, the timecode counter gradually becomes more inaccurate. This is the effect of
non-drop-frame timecode.
Drop-frame timecode keeps the timecode count accurate. In drop-frame video, frames 0 and
1 are omitted (dropped) from the timecode count at the start of every minute except 0, 10,
20, 30, 40, and 50 minutes, so that for example, the timecode count jumps from 00:00:59:29
to 00:01:00:02 instead of to 00:01:00:00. This is enough to keep the timecode count
synchronized with a 24-hour clock.