DVD Demystified

Essentials of DVD Production
TABLE 12.5
Typical project
assets
Type Assets Tasks
Video Source video tapes (movie, trailer, Digitize, clean up, encode
supplements)
Already encoded video (logos, Check
computer graphics)
519
Audio Original language source tape Digitize, synchronize
Foreign language source tapes Digitize, check length, synchronize
Commentary or other supplemental Digitize, synchronize
audio sources
Already encoded audio Check synchronization
Graphics Menu graphics Create/integrate graphics, create
button highlights
Supplemental graphics Create/integrate graphics, create
button highlights
Production stills and other photos Digitize, correct color, create button
highlights
Subtitles Text files Add timecodes
Graphic files Create timecode-filename mapping
file
If the video is of poor quality or contains noise, use digital video noise
reduction (DVNR) to improve it. Noise is random, high-entropy information,
which is antithetical to MPEG-2 encoding. Efficient encoding depends on
reducing redundant information, which is obscured by noise. Noise can
come from grainy film, dust, scratches, video snow, tape dropouts, crosscolor
from video decoders, satellite impulse noise, and other sources. Complex
video, including high detail and high noise levels, can be dealt with in
two ways: increase the data rate, or decrease the complexity. The DVNR
process compares the video across multiple frames and removes random
noise. After DVNR, the video compresses better, resulting in better quality
at the same data rate.
If possible, keep the production path short and digital. A frequent irony
of the process is that video is edited on a computer, then output to tape in
order to be encoded back into a computer file. If you use a non-linear digital
editing system (NLE), look into options for directly outputting DVDcompliant
MPEG-2 streams. Anticipate the need for aspect ratio conversion.
Make sure the various sources are in the proper aspect ratio (4:3 or
16:9), especially for assets that need to be edited together.
Make sure all the video on a disc (or on a single side) uses the same video
standard. Be prepared to convert from PAL to NTSC or vice versa. Good-