DigitalVideoAndHDTVAlgorithmsAndInterfaces.pdf

Consumer analog
NTSC and PAL 49
Consumer electronics manufacturers have taken great
liberties with video standards to achieve low-cost
consumer devices. In this chapter, I describe the
NTSC-4.43, PAL 60, and NTSC 50 schemes by which
foreign videotapes can be viewed. I describe degenerate
NTSC and PAL signals that are obtained when the
color subcarrier is incoherent with scanning. I introduce
the SCART connector common in Europe. Finally,
I comment on the heterodyne (or color-under) technique
used in consumer videotape recording.
Multistandard consumer equipment
The diversity of worldwide video broadcasting and
recording standards is a big nuisance to consumers.
Consumer electronics manufacturers have devised
schemes whereby 480i NTSC tapes can be played on
576i PAL equipment, and 576i PAL tapes can be
played on 480i NTSC equipment. These schemes can
be considered to be degenerate NTSC and degenerate
PAL. The schemes are features of VCRs, monitors, and
receivers: They are not tape formats, and they are never
broadcast.
I will briefly describe three schemes. The NTSC-4.43
and PAL 60 schemes are widely implemented in
consumer equipment in Europe and Asia; they allow
consumers in PAL regions to play NTSC tapes. The
NTSC 50 scheme is much less common; it allows
consumers in NTSC regions to play PAL tapes.
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