# What do Dolby Vision metadata levels L0, L1, L2, L3 and L8 mean, and which of them does a colourist author versus the system generate?

- id: art_01M5NP1BWWPQB9S7SJZ7BZ27BV
- type: article · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=metadata_checked, execution=not_run, review=unreviewed
- categories: T10, T12 · tags: none
- updated: 2026-10-24T00:47:40.950Z
- url: https://veyrul.com/articles/art_01M5NP1BWWPQB9S7SJZ7BZ27BV

Partially verified: the curator re-read none of the cited sources; S1, S2, S10, S13 rest on the producer's pinned reading. Dolby's own best-practice guide (v4.0, Dec 2019) describes a four-step process: grade the HDR master, run per-shot L1 analysis (automatic, three tonal values, not editable), optionally author trims (L2 in CMv2.9, L8 in CMv4) against named target displays, then deliver. L0 is the static global block; L3 offsets L1 in CMv4; in CMv4 files the old L2 block is computed for backward compatibility. Netflix's partner page (snapshot 2026-07-26) says L1 is required on every shot and the SDR 100-nit L2/L8 trim values are not required. FFmpeg's header and dovi_tool's README independently label which levels are per-frame dynamic and which are static.

Partially verified: the curator re-read none of the cited sources; S1, S2, S10, S13 rest on the producer's pinned reading.

Dolby's own best-practice guide (v4.0, Dec 2019) describes a four-step process: grade the HDR master, run per-shot L1 analysis (automatic, three tonal values, not editable), optionally author trims (L2 in CMv2.9, L8 in CMv4) against named target displays, then deliver. L0 is the static global block; L3 offsets L1 in CMv4; in CMv4 files the old L2 block is computed for backward compatibility. Netflix's partner page (snapshot 2026-07-26) says L1 is required on every shot and the SDR 100-nit L2/L8 trim values are not required. FFmpeg's header and dovi_tool's README independently label which levels are per-frame dynamic and which are static.

Curator qualifications: Partially verified: the curator re-read none of the cited sources; S1, S2, S10, S13 rest on the producer's pinned reading. Curator GET 2026-10-23 of the sources not re-read (mechanical source evidence, not semantic verification): S1: HTTP 200, bytes equal to the producer pin; S2: HTTP 200, bytes differ from the producer pin; S10: HTTP 200, bytes differ from the producer pin; S13: HTTP 200, bytes differ from the producer pin.

Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

```json
{
  "citations": [
    {
      "url": "https://professional.dolby.com/siteassets/pdfs/dolby_vision_best-practices_colorgrading_v4.pdf",
      "note": "candidate evidence excerpts"
    },
    {
      "url": "https://partnerhelp.netflixstudios.com/hc/en-us/articles/360058735254-Dolby-Vision-Metadata-Overview",
      "note": "candidate evidence excerpts"
    },
    {
      "url": "https://github.com/FFmpeg/FFmpeg/tree/5fd305b8f4214765500f6f6c50a52cf950cb049d",
      "note": "candidate evidence excerpts"
    },
    {
      "url": "https://github.com/quietvoid/dovi_tool/tree/fd0b28c420d6deceb4be4cb0257fb898504afaa0",
      "note": "candidate evidence excerpts"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] Dolby's own best-practice guide (v4.0, Dec 2019) describes a four-step process: grade the HDR master, run per-shot L1 analysis (automatic, three tonal values, not editable), optionally author trims (L2 in CMv2.9, L8 in CMv4) against named target displays, then deliver. L0 is the static global block; L3 offsets L1 in CMv4; in CMv4 files the old L2 block is computed for backward compatibility. Netflix's partner page (snapshot 2026-07-26) says L1 is required on every shot and the SDR 100-nit L2/L8 trim values are not required. FFmpeg's header and dovi_tool's README independently label which levels are per-frame dynamic and which are static. · locator: candidate evidence excerpts · source: https://professional.dolby.com/siteassets/pdfs/dolby_vision_best-practices_colorgrading_v4.pdf

Rights:
- documentation: license=unknown hosting=permitted redistribution=permitted modification=unknown training=unknown · Applies to this original summary only, not to the cited sources.

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