It will be interesting to see how this plays out. Dolby Vision is actually a mess of a standard, with several different not-quite-compatible "profiles." Streaming video is Profile 5, UHD Blu-ray Discs are Profile 7[1], and iPhone Dolby Vision is Profile 8. Profile 7 cannot be converted into Profile 5 [completely incompatible and different algorithms!], devices that implement Profile 5 can't necessarily play Profile 7, but Profile 7 can with difficulty be theoretically converted into Profile 8 which is basically stripped-down Profile 7 with quirks[2]. Basically, Dolby Vision is fragmented within itself. Fun stuff.
[1] And within Profile 7, there is the difference between the MEL (Minimum Enhancement Layer) which just adds HDR data, versus the FEL (Full Enhancement Layer) which actually adapts a 10-bit core video stream into a 12-bit one for FEL compatible players. Not all Profile 7 implementations can handle FEL, but can handle MEL. So even the profiles themselves have fragmentation. FEL and MEL are, within Profile 7, actually HEVC video streams that are 1920x1080 that the player reads simultaneously with the 4K content. So a FEL/MEL player is actually processing 2 HEVC streams simultaneously, so it's not a huge surprise why it isn't used for streaming DV.
[2] Profile 8 comes in 3 different versions, Profiles 8.1 through 8.4. 8.3 is not used. Profile 8.1 is backwards compatible with an HDR10 stream, Profile 8.2 a SDR stream, and Profile 8.4 an HLG stream. Big surprise that iPhone uses 8.4 because HLG can be seamlessly converted into SDR or some other HDR formats when necessary.
[1] And within Profile 7, there is the difference between the MEL (Minimum Enhancement Layer) which just adds HDR data, versus the FEL (Full Enhancement Layer) which actually adapts a 10-bit core video stream into a 12-bit one for FEL compatible players. Not all Profile 7 implementations can handle FEL, but can handle MEL. So even the profiles themselves have fragmentation. FEL and MEL are, within Profile 7, actually HEVC video streams that are 1920x1080 that the player reads simultaneously with the 4K content. So a FEL/MEL player is actually processing 2 HEVC streams simultaneously, so it's not a huge surprise why it isn't used for streaming DV.
[2] Profile 8 comes in 3 different versions, Profiles 8.1 through 8.4. 8.3 is not used. Profile 8.1 is backwards compatible with an HDR10 stream, Profile 8.2 a SDR stream, and Profile 8.4 an HLG stream. Big surprise that iPhone uses 8.4 because HLG can be seamlessly converted into SDR or some other HDR formats when necessary.
https://professionalsupport.dolby.com/s/article/What-is-Dolb...