Fox Sports has announced it would be televising Thursday Night Football games in 4K HDR. How they are getting there is interesting. They are capturing the games in 1080p/60 Hybrid Log Gamma (HLG) and up converting the signal to 2160p/60 for distribution via Over the Top (OTT) and several closed system distributors such as Direct TV and Verizon Fios. The first game will be on Thursday night September 26.
The original concept for HLG was a single signal could be sent out that would be compatible with all existing SDR sets and produce an HDR picture on sets equipped with HLG decode capability. Since it is a single signal it can only have one color system. Unfortunately SDR and Ultra HD SDR have two different color systems so what Fox Sports appears to be doing is capturing in the UHD 2020 color space at 1080p/60 for the HDR signal, then converting it to a separate 720p/60 HD color space for the over-the-air broadcast on Fox. The 1080p/60 HDR signal will be up converted to 2160p/60 by Fox for distribution.
The up conversion to 4K prior to making it available to the OTT would seem to be a numbers game. Just let the TV sets do the up conversion and keep the bit rate need for OTT down. Widescreen Review Video Technical Editor, Joe Kane, has long felt the implementation of HDR in the ATSC 3.0 broadcast system should be 720p/60 and or 1080p/24 or 60.
This could be another case where only a handful of viewers will see the broadcast in HDR. A quick online search suggests LG, Samsung and maybe Sony UHD HDR sets are initially equipped with HLG decoders. How many of those are connected to sources with the bit rate capability and or subscribe to this kind of content?