DigitalVideoAndHDTVAlgorithmsAndInterfaces.pdf

SMPTE 274M, 1920 × 1080 Scanning
and Analog and Parallel Digital
Interfaces for Multiple Picture Rates.
SMPTE 295M, 1920 × 1080 50 Hz
Scanning and Interface. (Despite
having “50 Hz” in its title, this
standard includes 25 Hz progressive
scanning.)
1920×1080 HDTV 47
This chapter details a family of high-definition television
systems standardized in SMPTE 274M. The systems
have image format of 1920×1080, an aspect ratio of
16:9, and square sampling.
HDTV equipment based on 1125/60 scanning and
1920×1035 image format, with nonsquare sampling,
has been deployed for several years and is standardized
in SMPTE 240M. This system can now be considered an
obsolete variant of 1080i30 or 1080i29.94 having
1035 picture lines instead of 1080, nonsquare
sampling, and slightly different colorimetry.
SMPTE 274M represents agreement on colorimetry
according to the international standard Rec. 709.
Previous revisions of SMPTE 274M allowed use of
240M color and luma parameters on an “interim” basis.
It will take some time for manufacturers and users to
complete the transition to the new standard.
Experimental HDTV systems in Europe used 1250 lines
(twice 625), often with 1920×1152 image structure.
The commercial success of 1920×1080 image structure
led to the development of SMPTE 295M, which defines
interlaced or progressive systems for 1920×1080 image
data in a 1250-line raster. 1250-line scanning has, not
surprisingly, failed to see commercial deployment. Since
SMPTE 274M includes the 25 Hz frame rate (as well as
23.976, 24, 29.97, 30, 50, 59.94, and 60), I urge you to
avoid SMPTE 295M, and to use the 1125-line scanning
of SMPTE 274M instead.
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