I just created a DCP but got this back from QC at TCH Labs (TASA certifying for volume). I didn’t make any changes in DCP-o-matic to what I normally do. This appears to be second time this has happened. I'm now concerned any DCPs I put out will be quieter than they are supposed to be...
There is a 5.1 mix there, but it is still a bit softer than what I certified from just the audio stems alone. Any idea why that might be?
And this is from Deluxe if this provides any additional info that might be applicable to the problem -- if not guidance on what that means would be appreciated too!
We wanted to raise that our QC team has noted the below , we will proceed as is and please let us know if you would like to redeliver. Please let us know how you would like to proceed.
Note:
17a57381-a326-4a08-9210-a3ad5e5d82c9
No GB on CTT .
Trailer has GB at HD
Quick shot: It's true that the DCP is roughly 2dB softer than your source material. Usually, DCP-o-matic doesn't do that unless you apply a manual gain change. I need to look into the files more closely to find out wether it's a global gain change or only in individual tracks.
Now, that is tested against TASA maximum loudness spec, and 2dB softer than 82LEQ(m) is still reasonable (that is, LOUD). TASA LEQ(m) is not a technical spec that needs to be met in order for the DCP to be technically correct. It's just a maximum loudness recommendation.
That is, I see no reason not to distribute this DCP. Unless you are providing service to a client and you have strict TASA maximum loudness guarantee in your contract with that client and he might actually complain about not hitting the spec exactly.
Which DCP-o-matic version did you use to create this DCP? 2.16.59 as indicated in the metadata files?
Okay, using 2.16.66 (but I don't believe 2.16.59 does anything different) I get exactly the same levels when I run your audio files into a DCP. Same peak, same LUFS values as on the input files. I can only assume that levels of your audio files did have a manual gain adjustment applied 'somewhere in-between'.
The Deluxe statement has nothing to do with audio levels. It is rather ambiguous. I believe they don't like something about the DCP naming. You should request some details regarding GB, CTT, etc. Again, I don't believe this is something to worry about.
It appears that "GB" means "green band" i.e. USA-style ratings card and CTT is "content title text". I have not the faintest idea why they think communicating with customers using such acronyms makes any sense. Or rather, I do have an idea, but it is a bit uncharitable.
I looked at the MOV, extracting its audio streams with FFmpeg and they seem to be the same level as in the DCP. So it does rather look like some gain is being introduced between the original WAVs and the MOV.
Not sure if I understand - you experience a level differenceonly after an MP4/ProRes Export?
Even if that would be the case - why do you care about proper DCP levels in such an export?