CMU (Content Mapping Unit)

The CMU (Content Mapping Unit) is the engine that applies Dolby Vision mapping: it takes the HDR master plus the L1/L2 metadata and produces the tone-mapped output for a chosen target display. Historically it was a dedicated Dolby hardware box in the grading suite, driving a second reference monitor so the colorist could see the SDR trim live. Modern DaVinci Resolve does it internally — the “tone-mapping preview” in a Dolby Vision QC pass is the CMU running in software. The term still shows up in specs and older workflows, so knowing it means “the mapping engine” keeps you fluent. It’s what turns your one HDR grade, plus its trims, into a correct picture on every class of display.

First used in: 3.7 · Dolby Vision & derived deliverables