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This topic comprises 2 pages: 1 2
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Topic: mono sound on DCPs of (older) Universal Studios titles
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Paul H. Rayton
Expert Film Handler
Posts: 210
From: Los Angeles, CA , USA
Registered: Aug 2003
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posted 04-04-2012 04:14 PM
In case your venue books any of the catalog (a/k/a "legacy", or historic) DCPs from Universal, there is a bit of an issue concerning the mono sound that's currently on these copies, and you might wish to be aware of it. We discovered this recently when running some of the older Marx Bros. titles, such as "Monkey Business" (1931) and "Duck Soup" (1933). I also observed it last week with their DCP of Orson Welles' "Touch of Evil" (1958).
Somehow, the DCPs that they've created to date have been mastered with the single channel mono sound put into "L" and "R" channels -- and not in the center channel! You can visually observe this on your server or audio system when you play these back, as you'll see activity in L and R, but nothing in C. Apparently they thought -- incorrectly -- that these (discrete) channels would sum together, a la LT/RT, and come out the center. Wrong. It plays to hard left and to hard right, creating an "out of balance" audio sensation in the auditorium, except for those (few) seats that are precisely on the centerline of the theatre.
Universal has said that they will be correcting this problem, starting now, but that it may take "a while" for the DCPs already created incorrectly to be fixed...
Meanwhile, if you want to remedy this for YOUR show and have the sound play through the center channel, there are a few alternatives: physically re-patch your audio paths (if you have that capability), or set your D to A converter to "Pro-Logic" (or similar), which will give a mostly center channel playout, or, at least in the Dolby DMA8s, you can go to the channel assignment page of the settings and re-route the audio from one of the active channels and send it to "center". (This presumes that you have the Dolby software, and know how to work it, etc.)
In my own case, initially trying the Pro-Logic mode, I was observing a good amount of audio leakage into the surround channels, and so actually turned off all amps except the center channel. For my next screening, I left it discrete, but sent one channel into center, via the software re-patching, and that was fine.
Universal promises that, from this point forward, they'll make these DCPs correctly. However, for for the moment, it's something you can be aware of to "fix", if and when you get any of these movies...
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Manny Knowles
"What are these things and WHY are they BLUE???"
Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002
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posted 04-06-2012 07:05 AM
If you have a DCP300 processor, you can create a Mono Preset, which routes one channel to Center and ignores the others. I actually had to do this very recently. [If needed, you could create two separate presets for mono: One with Academy filter, one without.]
DCP's of older titles should really be delivered so that these workarounds aren't needed. Especially since the digital rollout is probably going to put the final nail in the coffin of projection as a professional field. These things are going to have to run themselves. To that end, Lt/Rt's should be delivered as LCRS (preferably from the original print master), with the surround channel present on both legs of the Ls/Rs pair. And, of course, Mono should be delivered so that it is present only on the Center channel (Pair 2, Channel 1) with the proper filtration already applied. Et cetera.
The DMA8plus provides an option for handling 2-Channel Dolby Digital as an Lt/Rt but, if you run into one of those situations where you're playing a DVD/Bluray with a mono soundtrack that was created as a Dolby Digital 5.1 (with unused channels containing silence) it's not going to be possible to decode that bitstream as Pro Logic. This is another case where the Mono Preset may be useful.
If it's really an Lt/Rt that you can't decode, and you run it as Lo/Ro, the dialogue will be subject to the precedence effect. Which means that, from most seats, the dialogue will appear to come from one side of the screen.
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Paul H. Rayton
Expert Film Handler
Posts: 210
From: Los Angeles, CA , USA
Registered: Aug 2003
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posted 04-06-2012 10:16 PM
"Zoot Suit" was ... wouldn't you know ... a Universal movie. But it also was originally released with 70mm prints, so I'd almost start to wonder if it had some kind of stereo in that LT/RT that you are seeing. Of course, it's not **SUPPOSED** to be mastered that way, but Universal was a bit slow in sorting this issue out. If you have a chance, you might try playing it and watching (and/or listening to) the sound to see if there is any stereo in there. Otherwise, it seems like you, technically speaking, should do the re-patching thing, as much of a nuisance as that can be. Just my two cents.
BTW, if you take a look at the DCI specs (which can be seen at Official DCI Specs, esp. section 3.3.3, on pages 30, 31, and 32, they specify the exact "channel mapping", their term for channel assignments. In adjacent pages you'll find additional tech specs that studios are supposed to be following. Page 34, for example, goes into the details of the WAV files, and how they must be uncompressed, for example. It's all for the purpose of trying to make sure everything is "interoperable", but I have to wonder if they've been paying attention!
As a sidelight, in those pages you can also see that, at least as of the time of the publication (2008), the channel assignments were fully compatible and inclusive of traditional 5-across stage speakers, such as with 70mm prints. (This has been discussed in a couple of other threads, as well). It's too bad that now, it seems, everyone has forgotten those details, in their rush to get out proprietary 7.1, and 11.1 (and probably other) audio configurations, and which will probably have the effect of ending the standardization that DCI sought to bring to the situation!
I've actually heard exactly one DCP that had full 5-across sound, and it was great. DTS allowed for 5-across with their systems for legacy 70mm prints, and I'm kind of scratching my head for a reason as to why these DCPs of legacy movies have not had the proper stage channel configuration(s), only being (AFAIK) issued as 5.1s. It's really lame, because any theatre with the speakers and amps is already immediately ready to go, when they add the server. Makes me kind of upset! Sigh.
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