[viz] Add flag to use absolute nits for HLG videos [chromium/src : main]

1 view
Skip to first unread message

Andrew Ke (Gerrit)

unread,
May 9, 2026, 5:35:05 AM (yesterday) May 9
to ccameron chromium, Chromium LUCI CQ, chromium...@chromium.org, asvitki...@chromium.org, cc-...@chromium.org, jmedle...@chromium.org, penghu...@chromium.org
Attention needed from Andrew Ke and ccameron chromium

Andrew Ke voted and added 1 comment

Votes added by Andrew Ke

Commit-Queue+1

1 comment

Patchset-level comments
File-level comment, Patchset 1 (Latest):
Andrew Ke . resolved

Hi Chris, PTAL at this change. it adds a flag to disable normalising HLG HDR video brightness to OS SDR white. This way users can use OS SDR white at 100 or 140 nits etc without a darkened HLG video. Thanks!

Open in Gerrit

Related details

Attention is currently required from:
  • Andrew Ke
  • ccameron chromium
Submit Requirements:
  • requirement satisfiedCode-Coverage
  • requirement is not satisfiedCode-Owners
  • requirement is not satisfiedCode-Review
  • requirement is not satisfiedReview-Enforcement
Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings. DiffyGerrit
Gerrit-MessageType: comment
Gerrit-Project: chromium/src
Gerrit-Branch: main
Gerrit-Change-Id: Icd62ffbd3fbce5a81c9a9e80d59355a85781ab98
Gerrit-Change-Number: 7834306
Gerrit-PatchSet: 1
Gerrit-Owner: Andrew Ke <keya...@gmail.com>
Gerrit-Reviewer: Andrew Ke <keya...@gmail.com>
Gerrit-Reviewer: ccameron chromium <ccam...@chromium.org>
Gerrit-Attention: ccameron chromium <ccam...@chromium.org>
Gerrit-Attention: Andrew Ke <keya...@gmail.com>
Gerrit-Comment-Date: Sat, 09 May 2026 09:34:30 +0000
Gerrit-HasComments: Yes
Gerrit-Has-Labels: Yes
satisfied_requirement
unsatisfied_requirement
open
diffy

Andrew Ke (Gerrit)

unread,
May 9, 2026, 5:38:07 AM (yesterday) May 9
to Dale Curtis, ccameron chromium, Chromium LUCI CQ, chromium...@chromium.org, asvitki...@chromium.org, cc-...@chromium.org, jmedle...@chromium.org, penghu...@chromium.org
Attention needed from Dale Curtis and ccameron chromium

Andrew Ke added 1 comment

Patchset-level comments
Andrew Ke . resolved

Adding Dale for a look at the viz / media side of this flag as well. PTAL!

Open in Gerrit

Related details

Attention is currently required from:
  • Dale Curtis
  • ccameron chromium
Submit Requirements:
  • requirement satisfiedCode-Coverage
  • requirement is not satisfiedCode-Owners
  • requirement is not satisfiedCode-Review
  • requirement is not satisfiedReview-Enforcement
Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings. DiffyGerrit
Gerrit-MessageType: comment
Gerrit-Project: chromium/src
Gerrit-Branch: main
Gerrit-Change-Id: Icd62ffbd3fbce5a81c9a9e80d59355a85781ab98
Gerrit-Change-Number: 7834306
Gerrit-PatchSet: 1
Gerrit-Owner: Andrew Ke <keya...@gmail.com>
Gerrit-Reviewer: Andrew Ke <keya...@gmail.com>
Gerrit-Reviewer: Dale Curtis <dalec...@chromium.org>
Gerrit-Reviewer: ccameron chromium <ccam...@chromium.org>
Gerrit-Attention: ccameron chromium <ccam...@chromium.org>
Gerrit-Attention: Dale Curtis <dalec...@chromium.org>
Gerrit-Comment-Date: Sat, 09 May 2026 09:37:32 +0000
Gerrit-HasComments: Yes
Gerrit-Has-Labels: No
satisfied_requirement
unsatisfied_requirement
open
diffy

ccameron chromium (Gerrit)

unread,
9:06 AM (4 hours ago) 9:06 AM
to Andrew Ke, ccameron chromium, Dale Curtis, Chromium LUCI CQ, chromium...@chromium.org, asvitki...@chromium.org, cc-...@chromium.org, jmedle...@chromium.org, penghu...@chromium.org
Attention needed from Andrew Ke and Dale Curtis

ccameron chromium voted and added 1 comment

Votes added by ccameron chromium

Code-Review-1

1 comment

Patchset-level comments
File-level comment, Patchset 3 (Latest):
ccameron chromium . resolved

Sorry, this isn't the direction we want to go.

Absolute luminance rendering is only possible on Windows, so this feature can't be cross-platform.

Absolute luminance is also usable only in a reference environment, and almost no Chrome users operate in a reference environment.

Open in Gerrit

Related details

Attention is currently required from:
  • Andrew Ke
  • Dale Curtis
Submit Requirements:
    • requirement satisfiedCode-Coverage
    • requirement is not satisfiedCode-Owners
    • requirement is blockingCode-Review
    • requirement is not satisfiedReview-Enforcement
    Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings. DiffyGerrit
    Gerrit-MessageType: comment
    Gerrit-Project: chromium/src
    Gerrit-Branch: main
    Gerrit-Change-Id: Icd62ffbd3fbce5a81c9a9e80d59355a85781ab98
    Gerrit-Change-Number: 7834306
    Gerrit-PatchSet: 3
    Gerrit-Owner: Andrew Ke <keya...@gmail.com>
    Gerrit-Reviewer: Andrew Ke <keya...@gmail.com>
    Gerrit-Reviewer: Dale Curtis <dalec...@chromium.org>
    Gerrit-Reviewer: ccameron chromium <ccam...@chromium.org>
    Gerrit-Attention: Andrew Ke <keya...@gmail.com>
    Gerrit-Attention: Dale Curtis <dalec...@chromium.org>
    Gerrit-Comment-Date: Sun, 10 May 2026 13:06:37 +0000
    Gerrit-HasComments: Yes
    Gerrit-Has-Labels: Yes
    satisfied_requirement
    unsatisfied_requirement
    blocking_requirement
    open
    diffy

    Andrew Ke (Gerrit)

    unread,
    11:28 AM (1 hour ago) 11:28 AM
    to ccameron chromium, Dale Curtis, Chromium LUCI CQ, chromium...@chromium.org, asvitki...@chromium.org, cc-...@chromium.org, jmedle...@chromium.org, penghu...@chromium.org
    Attention needed from Dale Curtis and ccameron chromium

    Andrew Ke added 1 comment

    Patchset-level comments
    ccameron chromium . unresolved

    Sorry, this isn't the direction we want to go.

    Absolute luminance rendering is only possible on Windows, so this feature can't be cross-platform.

    Absolute luminance is also usable only in a reference environment, and almost no Chrome users operate in a reference environment.

    Andrew Ke

    Yup I agree that absolute nits is only possible on Windows. So I propose renaming the flag to HlgVideoSdrRelative (ON is current behaviour, OFF is don't normalise). HlgVideoSdrRelative = OFF can benefit macOS too, where currently Chrome HLG video can be darker than PQ, and 2.3x darker than HLG on Safari. https://issues.chromium.org/issues/511304750#comment5

    I understand the need for relative nits. But I think the normalising gain of SDR nits/203 can be inappropriate for some users. This results in users who are in a brighter than reference environment, but use SDR <203 nits, to get a darker than reference image. https://download.microsoft.com/download/8/0/6/8061224B-6EDA-4162-A5D4-FA9A779E732F/integrating-ambient-light-sensors-with-windows-10.docx says that in normal indoor lighting, 200 lux, users prefer 164 nits SDR. They get darker than reference videos despite being in a far brighter than reference environment.

    So, I think relative nits should allow the user to set the normalising gain (SDR white/ user setting). Or maybe just 2 presets, SDR white/203 or SDR white/100

    Open in Gerrit

    Related details

    Attention is currently required from:
    • Dale Curtis
    • ccameron chromium
    Submit Requirements:
      • requirement satisfiedCode-Coverage
      • requirement is not satisfiedCode-Owners
      • requirement is blockingCode-Review
      • requirement is not satisfiedNo-Unresolved-Comments
      • requirement is not satisfiedReview-Enforcement
      Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings. DiffyGerrit
      Gerrit-MessageType: comment
      Gerrit-Project: chromium/src
      Gerrit-Branch: main
      Gerrit-Change-Id: Icd62ffbd3fbce5a81c9a9e80d59355a85781ab98
      Gerrit-Change-Number: 7834306
      Gerrit-PatchSet: 3
      Gerrit-Owner: Andrew Ke <keya...@gmail.com>
      Gerrit-Reviewer: Andrew Ke <keya...@gmail.com>
      Gerrit-Reviewer: Dale Curtis <dalec...@chromium.org>
      Gerrit-Reviewer: ccameron chromium <ccam...@chromium.org>
      Gerrit-Attention: ccameron chromium <ccam...@chromium.org>
      Gerrit-Attention: Dale Curtis <dalec...@chromium.org>
      Gerrit-Comment-Date: Sun, 10 May 2026 15:27:43 +0000
      Gerrit-HasComments: Yes
      Gerrit-Has-Labels: No
      Comment-In-Reply-To: ccameron chromium <ccam...@chromium.org>
      satisfied_requirement
      unsatisfied_requirement
      blocking_requirement
      open
      diffy
      Reply all
      Reply to author
      Forward
      0 new messages