About Standard and High Definition DVDs
Standard definition (SD) DVDs provided most viewers with their first digital video
experience. The great video quality, interactive menus, and surround sound audio found
on current DVDs set a high standard for viewer expectations. Meanwhile, the establishment
of high definition (HD) video format standards and the increasing availability of HD
broadcasts have led to more and more viewers having HD video monitors, and even
higher expectations for DVDs.
These expectations, along with the development of improved compression technologies
and a blue laser technology that greatly increases a disc’s storage capacity, have led to
the ability of recording HD video onto a DVD.
Overview of Using DVD Studio Pro
But Aren’t DVDs Already High Definition?
In addition to traditional 4:3 aspect ratio video, traditional DVDs support widescreen
16:9 video, which is often mistaken for being high definition. The 16:9 video used on
current DVDs, however, is the same resolution as the 4:3 video, which is the same as
the standard NTSC and PAL broadcast resolutions. The 16:9 video must be anamorphic,
which makes it appear horizontally squashed when viewed on a 4:3 monitor.
This leads to a logical next question—what constitutes high definition video? While
most HD video formats use a 16:9 aspect ratio, what generally defines whether or not
they are HD is the resolution.
Video resolutions that result in more pixels per frame than are used in SD-based DVDs
are considered high definition. There are two common HD vertical resolutions: 720 lines
and 1080 lines (used for both NTSC and PAL). These compare to NTSC’s 480 lines and
PAL’s 576 lines for SD video.
As with SD-based DVDs, the scanning method used on HD-based DVDs can be interlaced,
with a video frame containing one field with the odd lines and another field with the
even lines, or progressive, where each frame is complete. Not all HD formats support
progressive scanning, however. See
Supported Video Resolutions
for details on supported
SD and HD video formats, including frame rates and scanning methods.