Fun WIth HDR !

[James Gardiner]

hello all.
thanks for getting the images to work.
Some comments..
SDR and HDR dcps are both in P3 colour, so the colours shown should be close. the difference is how the code values are read in terms of brightness levels.

I would image the SDR in HDR mode look way over saturated in some areas.

resolve should read in a SDR DCP without issue. make sure your feeding PQ levels in P3 colour space into a J2K encoder and you should get a clear conversion to a HDR capable DCP of the content.

render to TIF and use DCP-O-Matic would likely work.
resolve wise you would need to not use the render to DCP method as it targets SDR and will automatically apply the required transforms. I would need to look at resolve and see if the conversion can be avoided and it just J2K what you give it. I am sure it's possible but exact config I am not sure. have not tried.

technically a conversion from SDR to HDR can be done with a basic automatable conversion. your just dropping an SDR image into a bigger container and making the right adjustments so it appears as the equivalent brightness in the wider luminance levels.

on barco and pausing playback when you switch away from the player. I wish thay would make this an option you can turn off. everyone hates it as this limitation does not exist on any other player. Barcon considers it a feature as it's more integration. yes maybe but it's not how every other system works.
Make it an option please barco.. I know you will be reading this.

[Ioannis Syrogiannis]

[...]
Make it an option please barco.. I know you will be reading this.

+1
It's not only "the competition does it, so why not you", it's also a missing function that brings headaches to the users and schedulers.
Yet, in regards to your confidence, James, that Barco will be reading this... after Tom Bert left the company, I don't know of anyone participating here that has a voice in Barco. Of course, you know more people than I do and it might be that you know a guy who knows a guy.

Jim, that quick-lunch-brake time you are waiting for SDR<>HDR should have reminded you the series one one-axis-at-a-time lens' changes. Annoying, but common practice, once upon a time. Admittedly, when advances were made on one side of the cinema technology, drawbacks on another seem to stand out even more. It's without doubt a matter that will be ironed down. The question is, will it take software optimization only, or hardware as well...?

Servers were using "2D content in 3D mode" presets for 2D trailers to work on 3D SPLs. I don't imply that SDR and HDR works the same way, but it would have been a nice feature to be added to HDR SPLs, wouldn't it?

[Steve Guttag]

When I first encountered the ICMP "feature" whereby the server doesn't work (playback) if you are not selecting the server on the projector, that was a big "ding" on the server. I brought this up to Barco, at the time and explained how that simply wouldn't work in many/most of our venues that do any sort of festival work. I wanted them to provide an option to disable that feature. It was explained to me then that it was intrinsic to the design of the ICMP that how it works when on HDMI ports (or SDI) is that it is unable to run the player itself, as if it transforms its resources around.

The was before they came up with a work-around (for some cases) where you can use their pattern-black to start a show and get the projector into a "Media Player" format before the first piece of content. So, for those uninitiated to the ICMP, if you build a playlist with say a pattern black and then a trailer and then a feature and you are in an HDMI format (preshow content)...the show starts but you don't have a cue to switch the projector to media player...when the player gets to the trailer (or any non pattern black), the show is over. If you have a suitable cue that puts the projector into a media player format, then the projector switches and the show runs as it would in any other situation.

For commercial cinemas, you can get away with this as you would always put your Flat or Scope cues in at the beginning but they have to be on the server's internal pattern black, not just a black MOS content.

And, while you're fixing that...put the Effing taillights back on the projectors!

[Carsten Kurz]

The Sony, that Jim operated in this booth before, had no problem to continue playing DCP (incl. audio) while it was switched to one of the two HDMI inputs. Format changes were also very quick (one or two seconds). Wondering wether on this specific projector, the laser light source will need to be adjusted and thermally stabilised for every format change, and maybe that is what takes some time. This task may take longer to stabilise than a current change for Xenon or UHP bulbs.

But this is just what happens when you change to a new platform. New skills to learn, new detours to take. We use both a Barco ICMP and a Sony and I need to take different routes with them for special events. Our Barco ICMP/S2K projector is very slow changing sources and tracking alt signals compared to the Sony.

[Ryan Gallagher]

SDR and HDR dcps are both in P3 colour, so the colours shown should be close. the difference is how the code values are read in terms of brightness levels.

I would imagine if we were given such additional content as a P3 DCP we would be less in the weeds, and it might just be a contrast difference on screen one can “live with” for these extra moments,

But what Jim and us festival/special event houses will stumble with (as with Jim’s example), are slides or clips provided as rec709 mov/hvec videos and sRGB png/jpegs. Played in a quickly made SDR DCP they are “fine”, you just don’t have the full P3 color ranges, but apparently when played in Barco’s LS HDR modes the same rec709/sRGB having DCP is very much not passable in a jam.

I wonder what if any difference there would be if you forced the video DCP into FULL color, despite the rec709 content, maybe it would move the needle back into passable territory with a one step method using DOM? I'm not sure what you could tweak for the stills, as they are already sRGB/Full range in DOM.

[Ryan Gallagher]

FYI, other than dealing with HDR blu-rays, this is the only thread over on DOM's forums about making DCPs for non-standard new HDR projectors.
https://www.dcpomatic.com/forum/view...rco+HDR#p12278

The tip about manually setting a luminance value to 14 in the DCP metadata->Advanced tab might get you somewhere, if Barco will use that value to do some translation when in HDR modes?

It seems at least one other person ran into this being useful to avoid an error with Dolby Vision type systems. DOM does not provide that luminance metadata value by default (because it was not required in the specs for SDR DCPs).

[Carsten Kurz]

We'll probably find out about that soon, but I'm sure that Barco is not relying on a generic mastering lumen number created by ISDCF 20 years ago in order to tell apart different 3D mastering luminance values. On IMAX systems, the signing certificates of the DCP are used to communicate an IMAX DCP, that will enable higher luminance and dual projector projection. That is a more robust system.

I had hoped that DCI/ISDCF and SMPTE would have agreed upon a generic HDR standard for the DCI ecosystem. We already had Eclair Color as the first proprietary HDR system. Now we see even more. The whole idea of single inventory went belly up. I guess Disney will be delighted when they set up the DCP mastering pipelines for AVATAR 3...

[Ryan Gallagher]

On IMAX systems, the signing certificates of the DCP are used to communicate an IMAX DCP, that will enable higher luminance and dual projector projection. That is a more robust system.

On the surface, it doesn't sound like the Barco is doing anything that "smart" in terms of detecting which mode it should be in based on a DCP or KDM for SDR vs their HDR implementation? Perhaps a feature and a bug. If it auto-detected but still took 11s to make the switch, you'd still be in the same pickle as far as show flow, with perhaps even less options to invent a solution.

[Ioannis Syrogiannis]

[...]
The was before they came up with a work-around (for some cases) where you can use their pattern-black to start a show and get the projector into a "Media Player" format before the first piece of content. So, for those uninitiated to the ICMP, if you build a playlist with say a pattern black and then a trailer and then a feature and you are in an HDMI format (preshow content)... the show starts but you don't have a cue to switch the projector to media player...when the player gets to the trailer (or any non pattern black), the show is over. If you have a suitable cue that puts the projector into a media player format, then the projector switches and the show runs as it would in any other situation.
[...]

Is it me, or does anybody else in here sees that as a way to "meet halfway"?
And what I mean by that is that it would be somehow (partially) accommodating to one's needs to be able to insert an "Alchemy black" of X minutes (or pause), and during that time to be able to change to a non-media-player source and screen what needs to be screened from an alternative source. That, making sure to change back to media-player before the end of that "Alchemy-black". But, that, would require those changes to not "break" the playlist running.
I suppose that people at Barco would have figured that work around, wouldn't they?

In addition to the Sony server, that Carsten mentioned, DSS doesn't mind the projector's input and puts the playlist into a pause, depending on Cat.745's input. Doremi IMB and IMS would change from HDMI to their screen server, if a DCP or SPL would start and wouldn't ask another projector preset for HDMI. Flexibility is nothing new on the subject, but I should mention here the benefit of DSSes being able to set an offset on the start of a DCP! I think Kodak had that last feature as well.
The less choices one has, the more the restrictions they have to deal with. That's why we can't resist to systems/environments that stay open to development and integration.

[Ryan Gallagher]

Going from ALT at start into an media player is a fine workaround for exactly one situation. People who have ALT preroll. But you'd be surprised how many situations fall outside of that one case in a special event screening, festivals, series of shorts, awards show, etc etc. The ability to go back and forth, and ideally have those cues and macros in an SPL is huge.

I have a festival coming in tomorrow that is a hodgepodge of shorts programs, panel discussions (probably with powerpoint), red carpet premieres etc etc. Granted each "program" can be dealt with individually, but still flexibility is pretty important!