Television

Television broadcast:
Generally refers to terrestrial radiation of television signals in one or more of the frequency bands defined by CCIR (and in the US reaffirmed by the FCC). The US has 59 television channels, each 6 MHz wide, for video plus correlated audio.

Television, digital component:
1. A signal format in which either the tristimulus value red®, green (G), and blue (B) signals representing the picture contents or a matrixed version consisting of the luminance (Y) and two color- difference signals (R-Y, B-Y) – are individually digitized and combined into a single data stream. SMPTE 1 25M describes a digital component television signal interface for 525- line/59.94 field/sec television systems.
2. Specifications for digital magnetic video tape recording of component digital video of 525-line or 625-line structure sampled at 13.5 MHz are grouped into the D-1 VTR standards. For 525- line, sampled at 13.5 MHz, the specifications are SMPTE 224M, 225M, 226M, 227M, RP 155, and EG 10. An index to the specifications for D-1, both 525-line and 625-line versions, is SMPTE EG 22. cf. CCIR Rec 601-2; CCIR Rep 624-4; component color; SMPTE EG 22; television, digital composite; television, digital, for studios.

Television, digital composite:
1. A signal format in which the signal matrix representing the picture contents consisting of the luminance (Y) and the two color-difference signals (R-Y, B-Y) modulated on a color subcarrier are digitized in the matrixed form as a single data stream. SMPTE 244M describes a digital composite television signal interface for 525-line/59.94 field/sec television systems.

2. Specifications for digital magnetic video tape recording of composite digital video of 525-line or 625-line structure are grouped into the D-2 VTR standards. For 525-line, sampled at 14.32 MHz, the specifications are SMPTE 245M, 246M, 247M, 248M, EG 20, and RP 155. An index to the specifications for D-2 is SMPTE EG 22.

Television, digital, HDTV:
An extensible family of compatible digital coding standards for studio use with high-definition television is under study and test by the SMPTE Committee on Television Signal Technology (S17). Digital representation of the 1125/60 system is documented in SMPTE 260M.

Television, enhanced (ETV) (also EDTV): 'The term enhanced television designates a number of different improvements applicable to 525/60-Hz and 625/50-Hz television systems. They include all television systems not specified in CCIR Report 624-4. Characteristics of Television Systems. and Report 801-4, The Present State of High-Definition Television, 'either with unchanged or new radiation standards’ and without specification of aspect ratio [CCIR Report 1077, 1990].

Television, high-definition (HDTV): 'A high-definition television system allows viewing at about three times the picture height, such that the system is virtually, or nearly, transparent to the quality of portrayal that would have been perceived in the original scene or performance by a discerning viewer with normal visual acuity. Such factors include improved motion portrayal and improved perception of depth … A high-definition television system generally implies in comparison with conventional television systems: (1) spatial resolution in the vertical and horizontal directions of about twice that available in CCIR Rec 601-2; (2) any worthwhile improvements in temporal resolution beyond that achievable with CCIR Rec 601-2; (3) improved color rendition; (4) a wider aspect ratio; (5) multichannel highfidelity sound” [CCIR Report 801-3, 1989].

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