With all the discussion lately over Quicktimes and NCLC tags lately I wanted to be able to change the color tags within Flame as a stopgap measure until ADSK gives us the ability to do so. I hope some of you find it helpful.
There are two scripts:
nclc.py(Acts as the middleman to send things to AMCDX)
nclc_mediahub_tag.py(Media Hub Hook)
How To Install:
nclc.pyto point to the correct location of where AMCDX is located. You shouldn’t have to touch this if you’re on a Mac. On Linux, the AMCDX link is the program itself so no need to “install” it per-se, just copy it somewhere like
nclc_mediahub_tag.pyto point to where
nclc_mediahub_tag.pyto where ever you keep your python hooks or the default
How To Use:
In Media Hub right-click on any .mov and you’ll see a new menu called “QT NCLC Tagging”. There are two options.
Rec 709, 2.4 Gamma (1-2-1)
This is the way FilmLight is exporting Rec709 QTs now. The difference is telling QT to use our gamma of 2.4 as the transfer as opposed to 1.85 which is what happens in the legacy way.
Rec 709, Legacy (1-1-1)
If you want to revert back to how Flame exports QTs.
I know ADSK is working on a fix for all this very soon but in the meantime, here’s a way to do it. Let me know if something doesn’t work. I’ve only tested the media hub script on CentOS 7.4 but it ought to work on 7.6 and OS/X fine.
Why It’s Needed
QuickTime on OS/X doesn’t display rec709 videos using a gamma of 2.4. This fixes that by telling it to.
QuickTimes have always looked slightly different on a normal laptop/computer monitor when compared to a broadcast monitor. Apple has tried to address this by using color tags within QTs and having their own version of color management called ColorSync. Basically it does what Flame does: What is this file & what is my display and I’m going to make it look right.
Historically all the apps we author content with have exported QTs with 1-1-1 tagging which is Rec709 across the broad. The problem is the gamma isn’t defined as 2.4 in this implimentation so there’s always been a shift.
I’m unsure why, but FilmLight seems to be the first to implement a better way to approach this issue which is tagging the video as 1-2-1 with a gamma of 2.4. The key here is the 2nd digit, 2, which tells ColorSync “Use the specified gamma as the transfer function”. In this case, 2.4 which is correct. ColorSync then knows to map this to whatever your client’s super awesome P3 Retina display is.
This video posted by Jean-antoine Lacolle does a great job explaining everything and showing the differences.
The sad fact is once it leaves us, it’s still throwing darts at a board. Some applications recognize ColorSync, some don’t. Vimeo, YT, etc…not at the moment, but maybe they will all the sudden. Oh, and of course this is only applicable for anything Apple. It sort of makes the argument of having online deliveries where you convert the gamma from 2.4 to 2.2 but that’s a whole different story.