HDR10+ (with NVEnc)

[Selur]

NVEnc doesn't support encoding any type of HDR itselfm tools like NVEncC or ffmpeg with nvenc encoding add HDR-10 encoding by adding the HDR-10 meta data to the encoded stream.
'hdr10plus_parser' allows to extract HDR-10+ meta data to a .json representation.
Thus reencoding a HDR-10+ atm. can be done by:

1. extracting the meta-data
   
2. reencoding the stream using x265 and adding the extracted meta data using x265s '--dhdr10-info' option.
   

What you want would need:
a. a tool which uses NVEnc and either supports extracting and adding HDR-10+ meta data
or
b. a tool which uses NVEnc and can add HDR-10+ meta data during encoding (then meta data would have to be presented separately; i.e. directly from the color grading tool used or by extracting it from an existing source and reusing it)
or
c. a tool which would allow to add HDR-10+ metadata to an already encoded stream.

Problem is I don't know of any tool which can do a., b. or c., so atm. I don't think there is a way to 'how to encode a movie in hdr10+ with NVEnc'.

You best hope is probably to hope that the author of NVEncC (https://github.com/rigaya/NVEnc) can and will add support for adding HDR-10+ meta data. (There's already a request for this over at https://github.com/rigaya/NVEnc/issues/119.)

Cu Selur