Streamers (Incl. Apple TV+) Should Heed This Apple Engineer’s Advice

The best practice is to enable EDR when there is both HDR content and potential EDR headroom available. Disable EDR when this is not the case. – Ken Greenebaum, Engineering Manager, Apple

Apple engineering manager Ken Greenebaum advises developers to enable EDR only when the user will see the difference. EDR stands for extended dynamic range and is used to refer both to the HDR representation and the HDR rendering technology used on Apple’s platforms. None of Apple TV+’s recent shows – Murderbot, The Studio, Carême, Your Friends & Neighbors, Dope Thief, Wolfs, Presumed Innocent – have any HDR intent whatsoever and are mastered to SDR levels, and the same goes for many, if not most Netflix Originals; yet they are streamed in Dolby Vision just the same.

“While we won’t go into details in this talk, floating point buffers used with EDR may be larger, and thus consume more bandwidth than the fixed point buffers that might otherwise be used. This, in turn, correlates to more power consumed. Even enabling CAEDRMetadata-based tone mapping involves an extra processing pass. This, in turn, increases latency and bandwidth. Simply, EDR, like many features, isn’t free and, as such, it should be used judiciously. The best practice is to enable EDR when there is both HDR content and potential EDR headroom available. Disable EDR when this is not the case. Similarly, choose HDR or SDR versions of content to open or stream based on if the EDR potential headroom, or even the current EDRmax headroom, is significantly greater than 1.0. Or, more simply, only enable EDR when the user will see the difference.” – Ken Greenebaum