-So for Lt/Rt if I want stereo I use it. So if I want to make a blu ray or DVD for submission purposes to film festivals, and I'm not sure if they'll have a 5.1 surround set up or not, then I would use my Lt/Rt transcoded to an ac3 file to author the disc.
No! Again, don't transcode the LtRt to anything, just use it as you would a standard wav stereo file with the exception of transcoding it! As far as DD is concerned, they don't need to have a 5.1 system setup. All HDTVs, DVD players and AV Receivers have a Dolby decoder chip inside, if you have not specified that you want a direct digital output on the TV/DVD player AND set the AV Receiver to 5.1 the TV/DVD player will assume a stereo system and automatically downmix the 5.1 to stereo. Most laptops and computers have a similar software based downmix feature but I can't guarantee that every computer will. In other words, If you've ever watched HDTV without a 5.1 system, an automatic stereo downmix is what you've heard as DD is the only way to include audio in HDTV. Now whether the auto-stereo downmix from your 5.1 DD sounds better than your LtRt, you'd have to check.
Either give it to them with a Lt/Rt (stereo) option, or 5.1 surround option. Both being ac3 files correct?
Nope!!
I asked him about LKFS readings, etc. and he mentioned for theatrical, just need to calibrate the room to 85db, which he did.
That's perfect! Providing of course that he actually has a cinema sized mix room, roughly 18,000 cubic feet or more. If he doesn't, if he just has say a really large living room sized mix room (or smaller), then he's screwed up big time! Common mistake, a little knowledge is dangerous! They read the Dolby specs (which say 85dBSPLC) and calibrate their room to it without understanding the vital importance of room size. The correct calibration for a smaller than cinema sized room could be anyhere from 82dB to 66dB. For this reason, the chances are very slim that your mix is at the correct level for cinema playback, it will probably be too quiet.
If he is wrong about this, I'm still caught in the middle as I just need to do the best I can with what info I have. So if you disagree, in your opinion what would be the best plan of attack since I don't have the correct tools?
He is obviously wrong, providing of course he doesn't actually have a cinema sized room! To be honest, without analysing the mix there's no way for me to know, your guess is going to be as good as mine.
As for the other options when creating ac3s, I spoke to the mixer and he said to set to -31, because -27 will turn up the mix 4 decibels. Right or wrong?
He's right that -27 will turn the mix up by 4dB compared to the DVD player/AV Receiver having it's Dial Norm switched off. As I said though, there's no way to know if -31 will actually turn the dial norm off on a particular DVD player/AV Receiver. If an AV Receiver does not respond to -31 and was last tuned to say a HDTV signal then it will be set to -24 (-23 in Europe), which is 7 or 8dB louder than off and your mixer's information would be quite wrong. Again, a little knowledge is dangerous! As we don't (in all likelihood) have any idea what level your mix is at, I would use -27, burn a DVD off, run it on your TV and see what happens. If it's really quiet (most likely) or really loud change the dial norm setting by 2 or 3dB, burn another DVD and try again. You won't get an accurate result this way but at least it will be very roughly ball park and listenable.
For the other array of options including Film Standard or Film Light, I'll probably go with Film Light then... and see how it sounds.
I'd still start with film light, although film standard is little more likely than I previously thought in light of the new info.
For the Audio Production Information, it's default is 105 db SPL peak mixing level. I should set that to 85db correct?
No, that's incorrect. The 85dB calibration is at -20dBFS, so peak would indeed be 105dB. Bare in mind, the "Audio Production Information" metadata is not a setting (unlike DRC or dial norm), it's just info and has no influence on playback. It's much the same as say adding the artists name to a music MP3's metadata.
For the DCP that's perfect then.. just going off the individual wav files.
Well, according to what you've stated your mixer has told you, it probably won't be perfect and might even be seriously imperfect, there's no way to know unfortunately. But as far as what you've got to do is concerned; yes, just use your individual wav files.
I'm not sure you'll still be thanking me after reading what I've written above! If there's anyway you can beg or cajole a test screening of your DCP in a cinema (preferably the festival cinema but any cinema is better than nothing) before your actual screening, I very strongly recommend that course of action. Better still, pony up some cash and see if you can hire an actual theatrical dub stage for a quick run through. It's the only way of knowing for sure if your mix is ball park correct, inaudible or deafening.
G
