Is DVD-Video a worldwide
standard? Does it work with NTSC, PAL, and SECAM?
IF YOU LIVE OUTSIDE OF NORTH
AMERICA PLEASE READ THIS BEFORE ORDERING THE DVD. THE DVD SOLD IN THE JUNK
STORE IS FORMATTED FOR NTSC (NORTH AMERICAN STANDARD)
The MPEG video on DVD is stored
in digital format, but it's formatted for one of two mutually incompatible
television systems: 525/60 (NTSC) or 625/50 (PAL/SECAM). Therefore, there are
two kinds of DVDs: NTSC DVDs and PAL DVDs. Some players only play NTSC discs,
others play PAL and NTSC discs.
All DVD players sold in PAL
countries play both kinds of discs. These multi-standard players
partially convert NTSC to a 60-Hz PAL (4.43 NTSC) signal. The player uses the
PAL 4.43-MHz color subcarrier encoding format but keeps the 525/60 NTSC
scanning rate. Most modern PAL TVs can handle this "pseudo-PAL"
signal. A few multi-standard PAL players output true 3.58 NTSC from NTSC discs,
which requires an NTSC TV or a multi-standard TV. Some players have a switch to
choose 60-Hz PAL or true NTSC output when playing NTSC discs. There are a few standards-converting
PAL players that convert from a NTSC disc to standard PAL output. Proper
standards conversion requires expensive hardware to handle scaling, temporal
conversion, and object motion analysis. Because the quality of conversion in
DVD players is poor, using 60-Hz PAL output with a compatible TV provides a
better picture. (Sound is not affected by video conversion.)
There are actually three types of
DVD players if you count computers. Most DVD PC software and hardware can play
both NTSC and PAL video and both Dolby Digital and MPEG audio. Some PCs can
only display the converted video on the computer monitor, but others can output
it as a video signal for a TV.
Bottom line: NTSC discs play on over
95% of DVD installations worldwide.
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