[Cin] Apple's EDR technology

[Phyllis Smith]

Wonder why they called it EDR - Extended Dynamic Range - instead of High
(for HDR)?

On Sat, May 31, 2025 at 2:05 AM Andrew Randrianasulu via Cin <
cin at lists.cinelerra-gg.org> wrote:

> https://m.youtube.com/watch?v=COxAt8pl_Xw
> "WWDC21: Explore HDR rendering with EDR | Apple"
>
> 34 min runtime
>
> What I found interesting that Apple used internal floating-point
> representation  with some values ABOVE 1.0f but those values probably can't
> leak into final video, at best they might remain inside OpenEXR image
> format captured at some point "as is" (?)
>
> There is textual (but more iOS /mobile oriented) description with pictures:
>
>
> https://medium.com/@maxwellyuchenlong/wwdc22-10113-10114-110565-explore-edr-on-ios-842ce9b5d500
>
> =====
>
> *Reference Mode*
>
> Reference mode is a new display mode for color-intensive workflows that
> pin settings and block out distractions to provide more objective and
> reliable reference results for a variety of common videos, such as color
> grading, editing, and content mode, similar to the reference presets on
> macOS.
>
> When you enable the reference mode, you will have the following features:
>
>    - The SDK peak brightness is fixed at 100 nits and the HDR peak
>    brightness is fixed at 1000 nits, so there is a 10x EDR headroom.
>    - Disables HDR tone mapping to provide one-to-one media display
>    mapping.
>    - Disables all display dynamic adjustments that occur to adapt to the
>    environment, such as True Tone, Auto Brightness, and Night Shift modes, and
>    instead allows the user to fine-calibrate the white point manually.
>
>
> === end of quotation ====
>
> At least back in 2021 Apple was still using Metal (their  Vulkan-like
> graphics API) and OpenGL for system-wide compositing, not sure if it
> changed or not lately?
>
> Still I am not sure how this provides HDR-like experience on SDR display
> (may be by using dynamic mapping?)
>
> Of course this is just tip of the iceberg I found in few minutes at the
> morning.
> --
> Cin mailing list
> Cin at lists.cinelerra-gg.org
> https://lists.cinelerra-gg.org/mailman/listinfo/cin
>
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