Static kCMSampleAttachmentKey_HDR10PlusPerFrameData 

pub unsafe static kCMSampleAttachmentKey_HDR10PlusPerFrameData: &'static CFString

Available on crate feature CMSampleBuffer only.

HDR10+ per frame metadata

The attachment is CFData containing HDR10+ metadata within an User Data Registered ITU-T T-35 SEI message (see ISO/IEC 23008-2-2020 section D.3.6) as little endian in the CFData. This attachment will override any HDR10+ metadata stored within the compressed data. The data shall start with the field itu_t_t35_country_code with the value 0xb5.

See also Apple’s documentation