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Recording (Windows): convert and tag screen and webcam colour as BT.709 #923

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#929
Closed
Recording (Windows): convert and tag screen and webcam colour as BT.709#923
#929
Labels
enhancementNew feature or requeststatus: fixed in mainWork is merged into main but may not be in a downloadable release yet.status: pending releaseMerged change is waiting for a packaged desktop release.
Milestone
v2.0.0

Description

@EtienneLescot
EtienneLescot
opened on Sep 30, 2026

Part of #920 (rank 5). Effort S, risk low.

Problem

  • The compositor decodes every recording as BT.709 limited range.
  • Screen track: no colour tags at all (color_range/space/primaries = unknown, measured). On the CPU path mf_encoder.cpp deletes MF_MT_VIDEO_NOMINAL_RANGE and MF_MT_YUV_MATRIX and lets the MFT choose the RGB32 → YUV matrix, which is not guaranteed BT.709 (hypothesis: NVENC or the Video Processor MFT may pick BT.601).
  • Webcam track: range and matrix tagged, but primaries and transfer read reserved (measured): MF_MT_VIDEO_PRIMARIES and MF_MT_TRANSFER_FUNCTION are never set.

Proposal

  • Pin the conversion to BT.709 limited and tag range, matrix, primaries (MFVideoPrimaries_BT709) and transfer (MFVideoTransFunc_709) on both tracks.

Verify

  • ffprobe -show_streams | grep color_ reads tv / bt709 / bt709 / bt709 on both tracks.
  • Solid red captured and read back as raw YUV: Y≈63, Cb≈102, Cr≈240 (BT.709). Y≈81, Cb≈90 means BT.601.

Activity

  1. EtienneLescot
    added
    enhancementNew feature or request
    on Sep 30, 2026
  2. EtienneLescot
    added a parent issue on Sep 30, 2026
  3. EtienneLescot
    added 2 commits that reference this issue on Sep 30, 2026

    fix(windows): encode H.264 High with BT.709 colour the compositor exp…

    37b52f7

    fix(windows): encode H.264 High with BT.709 colour the compositor exp…

    03b1f45
  4. EtienneLescot
    closed this as completedin c729834on Sep 30, 2026
  5. github-actions
    added
    status: fixed in mainWork is merged into main but may not be in a downloadable release yet.
    status: pending releaseMerged change is waiting for a packaged desktop release.
    on Sep 30, 2026
  6. github-actions
    added this to the Next Release milestone on Sep 30, 2026

  7. github-actions commented on Sep 30, 2026

    @github-actions
    github-actionsbot
    on Sep 30, 2026 – with GitHub Actions
    Contributor

    Fixed by #929 and merged into main.

    This change is assigned to the Next Release release milestone and is not necessarily available in the latest downloadable desktop release yet. It is currently marked as status: pending release until a packaged release containing it is published.

  8. EtienneLescot
    modified the milestones: Next Release, v2.0.0 on Sep 30, 2026

  9. EtienneLescot commented on Sep 30, 2026

    @EtienneLescot
    EtienneLescot
    on Sep 30, 2026
    CollaboratorAuthor

    Moved into v2.0.0 as part of the pre-release cut.

  10. Guo-astro
    added a commit that references this issue on Oct 1, 2026

    fix(windows): encode H.264 High with BT.709 colour the compositor exp…

    c729834
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