Rec. 2020
ITU-R BT.2020 Color Space
A wide color gamut standard for UHD/4K video, covering 75% of the visible color spectrum versus 36% for Rec. 709.
技术细节
Video rec. 2020 follows standard aspect ratios: 1920x1080 (1080p/FHD), 2560x1440 (1440p/QHD), 3840x2160 (4K/UHD). Bitrate requirements scale roughly with pixel count — 4K at equivalent quality needs ~4x the bitrate of 1080p. For web delivery, adaptive bitrate streaming (HLS/DASH) serves multiple quality levels based on network conditions. Most viewers watch on mobile screens where differences above 1080p are imperceptible, making 1080p the sweet spot for web video delivery.
示例
``` Video resolution standards: Resolution Pixels Typical Bitrate ───────────────────────────────────────────── 480p (SD) 854×480 1.5-2.5 Mbps 720p (HD) 1280×720 2.5-5 Mbps 1080p (FHD) 1920×1080 5-10 Mbps 1440p (QHD) 2560×1440 10-15 Mbps 4K (UHD) 3840×2160 15-30 Mbps ```