What is HDR Dual Carry?

HDR Dual Carry allows a single video stream to simultaneously carry the dynamic metadata for two HDR formats, SMPTE ST 2094-40 (HDR10+) and SMPTE ST 2094-10, embedded as separate SEI messages within the same encode. It is currently used with HEVC for ATSC 3.0 broadcasting and OTT streaming.

The practical benefit for broadcasters and distributors is significant: rather than maintaining two separate encodes to serve different HDR-capable devices, a single Dual Carry stream delivers the correct HDR experience to each device automatically. Each display reads the metadata track it supports and ignores the other, with no compromise to either signal.

Gray Television’s ATSC 3.0 broadcasts are a real-world example of Dual Carry in operation, simultaneously delivering both dynamic HDR standards to viewers across 40+ US markets from a single broadcast stream.