What Is Needed for DVD?
Before video or audio material can be used on a DVD, it must be prepared in one of the
formats defined in the DVD specification. This usually means MPEG-2 format for video
and Dolby AC-3 format for audio files (although you can also use standard PCM audio
formats, such as AIFF files, DTS format files, and MPEG-1 Layer 2 formatted files).
SD projects also accept the older MPEG-1 video format, most commonly seen in web-based
applications. Because MPEG-1 is about one quarter the resolution of MPEG-2 (352 x 240
as opposed to 720 x 480 for NTSC or 352 x 288 versus 720 x 576 for PAL) and utilizes much
lower data rates, the quality is significantly lower. However, MPEG-1 is useful for very long
programs if the picture quality is not of primary importance. Using MPEG-1 encoding,
you can fit many hours of material on a single DVD.
You cannot use MPEG-1 formatted video assets in HD projects.
MPEG encoding performs extremely complex calculations on your source material to
determine what can be safely “thrown away” with minimal impact on the visual quality.
As a result, MPEG encoding can produce files that are less than ten percent the size of
the source files, while still looking great.