HDR colour profile support on Mac

[SimonM]

I've noticed differences in the labelling of colour profiles between some UHD movies I acquired from the inter-webs and those I ripped myself with MKV and Handbrake.

For the ones I downloaded, the metadata lists the colour profile as BT.2020 PQ (9-16-9), and for the one I ripped myself it's stated as BT.2020 HDR10 (9-16-9). Further, macOS recognises the one I ripped as HDR, but appears not to for the other ones; or at least isn't labelling them as such. I base this on QuickView displaying an HDR tag on the movie I ripped (see screenshot) when it doesn't do so for the others with BT.2020 PQ (9-16-9).

So my questions are: is BT.2020 PQ (9-16-9) the same as BT.2020 HDR10 (9-16-9)? If so, is there a way to correct or change the labelling or naming scheme in the metadata so that it's supported? If not, is there any way to convert between the two without a full transcode? Or were the ones I downloaded simply sourced from an HDR UHD but converted to SDR during a transcode? That doesn't seem likely for some reason, but who knows? Or is the presence of the tag a cosmetic that isn't related to support or playback and is merely complimentary?

I'm blown away with the UHD I ripped and its appearance in macOS even though I don't have an HDR screen. It still looks far more dynamic than any SDR content I've seen on the laptop, and so the support in macOS for HDR10 at least seems pretty good. Other software don't appear to be doing a very good job, likely because they're not targeting Apple hardware or assume you're playing back on a fully HDR-compliant TV is my guess (but this is pure speculation).

Any insight on the discrepancy would be appreciated, but this kind of reinforces why it's nearly always better to rip something yourself from the source if you care about doing it right, to the highest standard, or at least to the settings that you prefer.

[dcoke22]

I assume when you say QuickView you mean the thing Apple calls Quick Look (https://support.apple.com/guide/mac-hel ... h14119/mac) where you highlight a thing in Finder and hit the space bar.

Do you have MediaInfo (https://mediaarea.net/en/MediaInfo) installed? What does it say about your various files?

Undoubtedly, Quick Look is using the same underlying libraries as Quicktime to play the files. In actual Quicktime, you can do a Show Movie Inspector (Command I) to see details about the file being played.

[SimonM]

I assume when you say QuickView you mean the thing Apple calls Quick Look (https://support.apple.com/guide/mac-hel ... h14119/mac) where you highlight a thing in Finder and hit the space bar.

Do you have MediaInfo (https://mediaarea.net/en/MediaInfo) installed? What does it say about your various files?

Undoubtedly, Quick Look is using the same underlying libraries as Quicktime to play the files. In actual Quicktime, you can do a Show Movie Inspector (Command I) to see details about the file being played.

That's the one. Quick View, Quick Look; I can never keep up with Apple's branding. I still call Spotlight Sherlock (RIP)!

Thanks for tip. I should've looked in QuickTime to see more metadata, sorry. So they all appear to be 10-bit HDR10 files and QuickTime says they have the same colour primaries and YCbCr matrix: ITU-R BT.2020; and transfer function: SMPTE ST 2084 (PQ). So that seems to imply that they are in-fact the same.

But for HDR type, the UHD I ripped says: HDR10 (Mastered for 1000 nits), whereas the downloaded ones only say HDR10. According to Wikipedia: "HDR10 is technically limited to a maximum of 10,000 nits peak brightness, however common HDR10 contents are mastered with peak brightness from 1,000 to 4,000 nits". Does that mean the other files may be mastered for a higher peak brightness and will therefore be less optimal when viewed on my Apple products? That could explain the lack of Apple's "HDR" tag blessing? I don't have MediaInfo so I'll check it out. It may provide further insight.

Another unrelated curiosity was that the movie I ripped had a frame rate of 25 fps, while the others were 23.98. I wasn't aware 25 fps was a standard frame rate but I guess it is.

[dcoke22]

Another unrelated curiosity was that the movie I ripped had a frame rate of 25 fps, while the others were 23.98. I wasn't aware 25 fps was a standard frame rate but I guess it is.

24 fps is what movies are typically shot in. 23.976 is what 24fps content is broadcast in color NTSC television (aka north American TV standard). 25 fps is the typical frame rate of PAL television stuff (aka Europe).

https://en.wikipedia.org/wiki/List_of_b ... eo_formats



RIP Sherlock.

[dcoke22]

Side note, lots of Apple laptops in recent years have had 'wide color' DCI-P3 (https://en.wikipedia.org/wiki/DCI-P3) displays. Without getting too deep in the weeds, the range of colors we can see is broader than a TV or computer monitor can show. What we now call SDR is defined to show a subset of all the colors of the visible spectrum. HDR displays are capable of showing a bigger range of colors than an SDR display (among other things). A display that can do the DCI-P3 spectrum is capable of showing more colors than a SDR display, but fewer than a HDR display.

[SimonM]

Makes sense then. The one I ripped was European and the others are probably ripped from American discs. Australia too is a PAL region if I'm not mistaken, so does that mean we get an extra frame rate on discs made for the local market?

I'm no closer to figuring out which peak brightness the other discs are mastered for, or whether it's 1000 nits and just not stated as such. Maybe it's because I based my transcode on one of the Apple device presets in Handbrake (the 2160p60 one) so it decided 1000 nits was the appropriate mastering setting. Do you have any further suggestions on this? I didn't buy that little utility because it looks pretty basic and had some mixed reviews. I'm sure there are freeware or better alternatives out there. Ultimately I plan to buy one of the discs and rip it myself to compare further, but it'd be handy to know beforehand what the situation is.

PS: My laptop is a 16" MacBook, so yes it supports P3. Like I said, the HDR 1000 4K disc I ripped looks amazing, even though I can't fully appreciate it, yet.