PQ and HLG have different luminance ranges (max 10k nits and max 1k nits resp). In GL, colors work in a normalised 0 to 1 scale, so for PQ content, 1=10k nits and and for HLG content, 1=1k nits.
This cl scales and normalises PQ content appropriately so that all HDR content works in the HLG luminance range. This fixes two things
1. Conversions between HLG and PQ are "fixed" (before the output colors looked too bright or too dark depending on which way you are converting)
2. color-altering effects will be able to work consistently across HLG and PQ content
1 is tested in this cl. 2 will be tested when ultra HDR overlays are implemented, both cases have been manually tested to ensure the output looks correct on a screen.
PiperOrigin-RevId: 636851701
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