Is my DCP file compatible with commercial movie theatres?

[COgilvy]

I have been trying to make a DCP file for a private screening of a movie I wish to watch in a theatre. After doing some basic research on Digital Cinema Initiatives and making multiple iterations with DCP-o-matic, I believe I have made an acceptable file. However, I first want to check with more experienced users to solve any issues now rather than later.

The DCP video has a Container of DCI Flat (1998x1080), a resolution of 2K, a frame rate of 24 fps, and a 150 mbit/s. There are two markers that mark end credits and first frame of moving end credits, as that was what DoM recommended when I made the original DCP. The DCP Audio has 8 channels, a LUFS of -28.41 and no processor.

The DCP is formatted as a SMPTE, has burned in English subtitling and to the best of my knowledge has no enabled encryption as I plan on moving the DCP with a physical drive.

My current concerns about the DCP is the audio as I can't tell if the file meets the requirements of 48 kHz sample rate or that it as has a 24 bit audio depth. I think I don't have acceptable dB levels, as audio analysis shows the graphs either be consistently above or below -20dB. (See attached)

DCP Audio Analysis.jpg

Can the audio characteristics of sample rate, audio depth and dB's be explained to me, and how I can fix them?

[carl]

Hi,

It looks OK to me. DCP-o-matic always writes 48kHz/24-bit audio, so you don't need to worry about that. The audio levels are always a bit of guesswork unless you can listen in a theater, but they look reasonable to me (the peaks are around -10dB and the average around -35dB).

Others on the forum have more experience than me of relating these audio plots to "real life", so somebody else might chime in.

[StephW999]

Hello, I don't see any problem with these levels.
However, the sound is only coming through the left and right channels.
but it's not a big deal, just unconventional.

[Perepiol]

Regards. I also see no apparent reason why your DCP couldn't be ingested by a cinema projector (the audio levels look correct—even a bit low, I’d say).
Do keep in mind, however, that your final DCP has 2.0 audio (which isn't an issue for a private screening). DCP-o-matic allows you to mix the left and right channels and route them to the center channel at -6dB; for an event involving dialogue, the cinema's center channel often yields better results.
End-credit markers aren't important for a private screening; otherwise, I don't see any major issues.
Best regards.[*][/url][/u]

[COgilvy]

A reply to StephW999 and Perepiol's comments,

Thank you for your answers on my DCP files audio. I now have a question on the sound channels themselves. The current DCP file was made from a preexisting one due to the fact I needed to have the file indicate it contained burned in English Subtitling, so I was able to take a picture of its audio channels. (See attached image)

DCP Audio Input.jpg

From what I can see is that there is audio going through all 8 available channels, so I'm not sure how both of you have reached the conclusion there is only audio going through the left and right speakers. I am concerned about this because Perepiol stated that a cinemas center channel yields the best results for "an event involving dialogue," which I take to mean as dialogue from the characters in the film.

Can channel audio be further explained to me, and how can I ensure that the sound will pass through multiple and correct channels when it is applied to a commercial movie theater?

[Perepiol]

Greetings. First, I should mention that I am merely an enthusiast when it comes to creating DCPs for my cinema.
You have an original 8-channel DCP (as shown in the attached diagram), but my question regarding the second DCP you created arises from the analysis diagram: the various original channels (all 8) ought to appear there, yet I only see 2 audio channels listed as analyzed—a fact reflected in the ISDCF naming convention (e.g., _FTR_F_ES-EN_ES-AA_51_2K_IND_20261013_LAB_SMPTE_OV).

[COgilvy]

Is the line at the bottom just an averaging of the left and right audio channels? And if so, how can I add the other six audio channels?

[Carsten]

I would guess that there simply is no signal in channels 3-8. That is actually quite common if the source for the original DCP had only stereo audio. There have been recommendations to always create an 8 or 16 channel DCP, and the result is that only the first two channels, Left and Right, carry signal, the others contain digital silence.

I wouldn't bother about the stereo audio too much. What is in that stereo audio - music, commentary?

The levels are acceptable - but I would probably raise them a few dB. -28 LUFS is a bit too soft in my opinion.I would aim for something like -23 +/-

Your concerns about audio sample rate and bit depth are unneccessary - it is one of DCP-o-matics prominent features that it conforms all sources to formats and parameters that are mandatory for DCI compliant DCPs.
So, even if your source would have 44.1KHz and 16Bit, the resulting DCP would contain transformed audio at 48KHz and 24Bit.