Making a DCP from a 2-channel stereo Blu-Ray

[Marcel Birgelen]

Deepwater Horizon did have a pretty impressive 7.1 mix already. I've never heard the Lexicon, but I've heard upmixes from other devices, like imm Sound (before Dolby killed it), I've heard Iosono's Wave Front Synthesis including their upmixing before Barco killed it. Something similar for live concerts is Areal and I've heard it both with a conventional PA system and in combination with Holoplot's X1 system (the system that's also in the Las Vegas sphere).

Of all the systems, the Iosono system was the most impressive, especially the specially crafted "binaural-sounding" demo stuff.

[Harold Hallikainen]

Wave Front Synthesis is a really interesting idea. I think it takes a LOT of loudspeakers and quite a bit of processing. It SEEMS like it could very accurately represent a sound outside the room, duplicating the wavefront as it "passes through" the walls. But, I don't see how it could represent a sound inside the room without largely going back to panning.

And, since you mentioned binaural, has anyone tried the Smyth Reaizer ( https://smyth-research.com/ ). I understant it is amazingly good, though I have never seen one.

[Jay Wyatt]

Pretty even split on opinions here. I am in the matrix decode / "upmix" camp.

Just because its a 2ch deliverable does not mean its Lo/Ro (Left Only / Right Only) format. It's far more likely this mix is printed Lt/Rt for broadcast rather than Lo/Ro. Lt/Rt by nature implies that a matrix decoder at the reproduction end is kosher. So the purist angle likely doesn't hold weight here.

Lt/Rt is still an expected sub-deliverable of the Home Theater print and I'd wager this was in place for your 1990 film released on Bluray.
Further, Lo/Ro only in a large theater can really be lackluster, particularly for dialogue -- and dialogue is king.

Legacy Workflow (5.1) -- Notice there is no L/R deliverable, only Lt/Rt
image.pngModern Workflow (IAB) - Lt/Rt still in play
image.png

[Marcel Birgelen]

Lt/Rt is still an expected sub-deliverable of the Home Theater print and I'd wager this was in place for your 1990 film released on Bluray.
Further, Lo/Ro only in a large theater can really be lackluster, particularly for dialogue -- and dialogue is king.

I think that MOST are in the camp that -if possible-, playing it with Pro-Logic or compatible matrix decoding option turned on is better than playing it in "vanilla Stereo", although speaking for others might be dangerous.

I think that MOST agree NOT to use the *current* upmix functionality in DCP-o-Matic, as the results are often worse than without upmixing. I'm not sure what the latest state of the upmixing in DCP-o-Matic is, but there used to be two versions. Both do similar things like ProLogic, but aren't exactly the same. Both are a bit of a poor-mans version of Pro-Logic.

The thing is, how much effort are you going to put into this and is it worth it? I recently did a presentation in a cinema, the presentation started with a 5-minute movie-clip I had prepared. This being presented in a proper cinema, I created a proper 4K DCP, including a 5.1 surround mix. As a backup, I also put the movie into Keynote, in 2.0 stereo.

The problem: The tech at hand didn't want to switch between presentation mode and "cinema mode" as he had other stuff to do. I couldn't be both in the booth and in front of the crowd at the same time, so I had to swallow my pride and I had to show this clip in Full HD over HDMI, window boxed on screen, stereo, only playing via the surrounds (to avoid PA feedback loops, in presentation mode), with much of the house-lights still up... The showman in me died a bit that day... On the other hand, it was just a 5 minute clip for a purpose and I had to accept the limitations given... I've done the same presentation in other locations, where I was lucky to even have working sound...

[Ryan Gallagher]

Yeah time and context is everything unless there is a push button way to do it as with some of the integration designs. I'd happily do it for preroll clips using DCP-O-matic. Doing it more properly for a feature ripped from a blu-ray might require a bit more resources and time than the end user projectionist or operator at the venue has time to deal with, notice etc depending. I do like how many methods this thread dug up though!