We have a movie coming in that will provide us with both an SDR grade and an HDR Dolby grade.
Any tips on how to manage the dual conforms so they stay in sync?
Along with graphics and BFX and whatever else I haven’t thought of.
Thanks,
Ted
Random, probably obvious ideas. Also possibly stupid.
–have two flames, one for each timeline, use path translation to “fool” flame two into picking up the SDR media instead of the HDR media, archive off one machine and load it into the other one.
–unlink whole timeline, relink to SDR media.
If you are doing a HDR Dolby vision grade, there only needs to be one timeline. You do all your work on the HDR Master and then the Dolby Metadata will automatically create the SDR version for you, all within Flame. Or am I missing something here?
Sorry - we’re not doing the grades, we’re receiving the grades.
I’ve updated my OP to make this more clear.
-Ted
Doesn’t make a difference. You would receive the HDR images, an edl/aaf and a Dolby Vision metadata file that you can load into Flame and will automatically create the SDR for you. The colourist would just do the Dolby analysis and the trims for you and produce the Dolby Vision xml.
You would preferably want to receive the grade as a 16bit source but 12bit will suffice also.
Seriously, doing the project using Dolby Vision will save you a ridiculous amount of time.
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Is the VFX done above or below the grade?
I’ve worked both ways for VFX too. Source media and VFX pipeline should stay 12 bit minimum but I’d still advocate for a Dolby Vision workflow. Unless the HDR & SDR edits are completely different with minimal common shots.
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@AdamArcher Out of interest in this scenario, how would you deal with text elements (Flame-generated captions etc)? Given that in HDR (PQ or HLG) white text needs to be lower than peak white (assume 1000nits) according to spec and in Rec709 it needs to hit peak white (100nits)?
Well, white text hitting 200-250 nits in HDR generally ends up not far off 100 nits after tone mapping. But the brilliant thing about Flame is you have a graphic layer in your timeline below the Dolby Vision layers in Flame that you would add your HDR graphics too, and you simply duplicate that layer and add it above your Dolby Vision trims. You turn off whichever graphic layer you are outputting at the time. In fact, in this scenario, I would do all the graphics for the SDR first, then simply have a Timeline FX setup with colour transform from SDR to HDR with a gain boost placed after it (around 120 usually does it) saved. Once you’re happy with your graphics in SDR, literally just duplicate that whole layer move it just below the Dolby Vision layers then add that setup.
I did a seminar about this a few years ago which covers HDR in Flame but more than happy to talk it through further if anyone is interested.
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Thanks Adam. I’d thought it was a bit more complicated than that. By far most of our Flame work is pregrade in ACES and (although I did a couple of jobs ages ago using the DoVi layer) I’d thought text etc was more tricky. It might simplify some of our workflows a lot.
Haven’t watched your HDR vid for ages so thanks for the reminder!
We’re testing a workflow as outlined by Adam above, only slight difference being that we will derive P3 PQ and HLG deliverables at the end:
- grade done outside Flame in DoVi P3 PQ D65
- grade exported as EXRs in AP0 + xml for SDR trim
- import to Flame, baking View Transform to P3 PQ into EXRs
- postgrade online
- export P3 PQ + Rec2020 HLG
It’s mostly working but the bit I’m stuck on is wanting to work in P3 PQ but simultaneously (broadcast) monitor in HLG (to see how that deliverable will look). Viewing Rules in Prefs > Colour Managment either don’t seem to allow the option, or the image doesn’t look right with the available options.
Is this is possible in Flame? ie work in PQ, but see it in HLG? I know you can in Baselight because that’s exactly what the colourist is doing.
@AdamArcher any thoughts?
Thanks!
Hmmm… I’m not entirely sure you can output both PQ and HLG out of Flame simultaneously. Don’t think you can do it in Resolve. Whilst we have Baselight as well, it wouldn’t be something we would do, especially given the need for 2x grade 1 HDR monitors to check it properly which would involve moving a 2nd display then recalibrating it for the room. Too much effort for something we wouldn’t want to do.
However, if you’ve got ACES AP0 graded material, the ACES transform from that into PQ or into HLG is ultra reliable. I just don’t think you will be able to view them simultaneously without sending the SDI through some secondary system/box to do a PQ to HLG colour transform. I know there are a few systems that can do live grading so assume that they could do a live transform.
I’ll ask the question though, why exactly do you want to compare them side by side? You are not going to get a perfect match and due to the nature of HLG, it will look a lot more different from monitor to monitor than PQ will (that is a fundamental difference between the two approaches to EOTF). I know some colourists like having the HDR and SDR side by side when doing Dolby trims but I think it would cause more complications then help. I actually need to walk out the room for at least 5-10 minutes when swapping between HDR & SDR to see them correctly.
Having delivered projects that required both PQ & HLG (as well as SDR), I’ve always viewed them separately with calibration settings on the display and been comfortable enough that there are no large discrepancies between them and that has been enough. Have always gone a PQ to HLG transform to deliver the HLG (as DoVi requires PQ). Never had an issue in that regard. So that’s how I would handle the HLG. Finish it in PQ then apply a PQ to HLG transform either on output or baked in on your timeline.
Sorry, didn’t explain properly.
Not looking to compare side-by-side or anything like that. Totally agree with all your points about the pitfalls and futility of that!
Our primary del is the HLG, so that’s what we (only) want to be looking at with the client while we do the work. But we want to be actually working in PQ until export, because the PQ > HLG conversion is more solid than HLG > PQ (so don’t want to bake it to HLG at grade export or Flame import), and obviously for the secondary PQ del, we don’t want to be going PQ > HLG > PQ.
Hope that makes sense?
Our plan B is just to monitor in PQ throughout (same as working), but it would be nice to be looking at the HLG (mimicking the eventual HLG export) as we go. Especially when checking the look of text, gfx etc.
That is a lot easier then. Assuming you have an HLG calibrated display it should be as simple as adding a layer to the top of your HDR stack (below any DoVi HDR to SDR layers) and simply apply a Colour Transform input transform gap effect there from PQ to HLG. I can’t remember off the top of my head if there is a P3D65HLG option in Flame so you may need to output a Rec2020/HLG signal and ensure your monitor is calibrated to that. Do all your work staying in PQ but monitor the output through the HLG transform. Alternatively you can setup an output viewing LUT that does the PQ to HLG and view through that?
I’ve tended to show clients what the HLG transform looks like so they are comfortable with that workflow, then do all the work and screenings viewing in PQ. Make the client comfortable and confident in the process then it makes life so much easier and there is no second guessing.
On the HLG projects I mentioned previously, the HLG outputs were actually done from Resolve as they were all IMF deliveries (with ProRes instead of J2K) to DPP specifications which Flame can’t do. As mentioned, everyone (including the BBC) were really happy with that process.
I’m not in front of a Flame right now and won’t be able to until Monday. More than happy to have a look for you then though if you still need help?
Pretty sure there isn’t. HLG is always Rec 2020 afaik.
Thanks for all this. I’ll try again today and probably look at the viewing LUT option first. I’ll let you know.
I’ll try and take a look Monday too if I remember. I did create something in the viewer for a Rec2020PQ transform at one stage just for an explainer.
As mentioned though, I’ve always thought that getting clients comfortable with the colour pipeline first, then viewing/working in your preferred colour space was always a lot better/easier.
Did more testing today.
Reluctant to use a gap CM transform, as it’s a bit clunky ensuring that you’re always viewing that layer (set to Secondary I guess) while working a client session, and also it’s at risk of accidents when the op forgets to disable it before export. Ha.
Did get an imported viewing LUT pretty much working - good enough for client session at least - or we have the option to just work P3 PQ all the way as you suggest. It looks the same at 1000nits on a Sony HX310 anyway (just need to check the behaviour of Flame-generated white captions in that regard).
Thanks again for the advice, Adam.