Rec. 2020
ITU-R Recommendation BT.2020, more commonly known by the abbreviations Rec. 2020 or BT.2020, defines various aspects of ultra-high-definition television (UHDTV) with standard dynamic range (SDR) and wide color gamut (WCG), including picture resolutions, frame rates with progressive scan, bit depths, color primaries, RGB and luma-chroma color representations, chroma subsamplings, and an opto-electronic transfer function.[2] The first version of Rec. 2020 was posted on the International Telecommunication Union (ITU) website on August 23, 2012, and two further editions have been published since then.[2][1][3][4][5]
Rec. 2020 is extended for high-dynamic-range (HDR) by Rec. 2100, which uses the same color primaries as Rec. 2020.
Technical details[edit]
Resolution[edit]
Rec. 2020 defines two standard image formats of 3840 × 2160 ("4K") and 7680 × 4320 ("8K").[2] These both have an aspect ratio of 16:9 and use square pixels.[2]
Frame rate[edit]
Rec. 2020 specifies the following frame rates: 120p, 119.88p, 100p, 60p, 59.94p, 50p, 30p, 29.97p, 25p, 24p, 23.976p.[2] Only progressive scan frame rates are allowed.[2]
Digital representation[edit]
Rec. 2020 defines a bit depth of either 10 bits per sample or 12 bits per sample.[2]
10 bits per sample Rec. 2020 uses video levels where the black level is defined as code 64 and the nominal peak is defined as code 940. Codes 0–3 and 1,020–1,023 are used for the timing reference. Codes 4 through 63 provide video data below the black level while codes 941 through 1,019 provide video data above the nominal peak.[2]
12 bits per sample Rec. 2020 uses video levels where the black level is defined as code 256 and the nominal peak is defined as code 3760. Codes 0–15 and 4,080–4,095 are used for the timing reference. Codes 16 through 255 provide video data below the black level while codes 3,761 through 4,079 provide video data above the nominal peak.[2]