Apple and Google developed a new HDR standard: Eclipsa Video

flatpanelshd.com

8 points·dmmalam··5 comments

If SDR is 32bpp, why can't HDR just simply be 64bpp? Or, 128, if that somehow isn't enough? I'm sure I'm misunderstanding but it seems like the whole thing has become very complicated with a lot of competing standards and not a lot of working together towards something simple that works for everyone.

SDR is 24 bit and HDR is 30 bit. However there seems to be some brightness metadata required to specify how bright 1023 is. What baffles me is that there seem to be five or six different standards for this metadata.

The problem isn't how bright should 1023 be. The problem is how bright should diffuse white be (aka graphics white or SDR white)? None of HDR10, HDR10+, or DoblyVision ever attemped to address that question. Which is a pretty important question to answer if you want to use HDR in a desktop / multi-window environment.

None of HDR10, HDR10+, or DolbyVision ever answered the question of how to adapt for varying ambient brightness levels, either, which is again a very important question to answer for portable devices like phones, tablets, and laptops.

> None of HDR10, HDR10+, or DolbyVision ever answered the question of how to adapt for varying ambient brightness levels, either, which is again a very important question to answer for portable devices like phones, tablets, and laptops.

Those are extremely niche use cases. Most normal people watch their TikTok and YouTube on a perfectly calibrated wide gamut HDR OLED in their darkened color grading room.

Bit depth is precision. HDR or SDR are the range. They are orthogonal concepts.

But at a high level you're basically asking "why doesn't scRGB exist" and, well, it does :) https://en.wikipedia.org/wiki/ScRGB (also called extendedSRGB)

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