This is topic mono sound on DCPs of (older) Universal Studios titles in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.


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Posted by Paul H. Rayton (Member # 1817) on 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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Posted by Aaron Garman (Member # 1653) on 04-04-2012, 04:49 PM:
 
Sounds like someone used to authoring discs for home use got the job. Too bad.

AJG
 

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Posted by Scott Norwood (Member # 30) on 04-04-2012, 05:01 PM:
 
Did they at least get the Academy filter right, or is everything super-hissy?
 

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Posted by Manny Knowles (Member # 1171) on 04-04-2012, 05:33 PM:
 
Yeah, I've run across this channel assignment issue with "home grown" DCP's too. Mostly with Lt/Rt's that need matrix decoding.

I keep a spare cable that lets me conveniently reroute things, if needed.

"Super-hissy" -- as in "Scott threw a super-hissy-fit when he heard that unfiltered mono!!!"
 

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Posted by Paul H. Rayton (Member # 1817) on 04-04-2012, 06:08 PM:
 
The Marx Bros. stuff was a bit hissy, but, really, since it was from 1930 or so, I didn't really have high expectations of superb audio...
 

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Posted by Terrence Meiczinger (Member # 5059) on 04-06-2012, 01:49 AM:
 
One of the issues with DCPs is there is no Mono option. It's stereo, then additional channels in even increments. So really, you'd go from stereo to 5.1, then 7.1 and so on. If you wanted mono, you'd need to create a 5.1 DCP with silence tracks on everything but the center. Kind of a pain.
 

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Posted by Antti Nayha (Member # 4980) on 04-06-2012, 04:10 AM:
 
Back in 2009, I received a festival feature as a mono DCP (= a 5.1 soundtrack with silence on the unused channels). When playing it back on a DSP100/DSS100 combination, there were LOUD cracks all along the film on the ”silent” channels. These cracks were seemingly random, but always appeared at exactly the same frames.

The same DCP had been playing fine at some other festivals, including Cannes. We were running the latest software on the Dolbys. We just turned off all the PA channels except center, and the whole thing remained a mystery.
 

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Posted by Manny Knowles (Member # 1171) on 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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Posted by Jesse Skeen (Member # 586) on 04-06-2012, 07:23 PM:
 
I've never understood why most mono films on DVD and Blu-Ray have been done with 2-channel Dolby Digital tracks which play through the center if you have Pro-Logic enabled. A few do it correctly with just one center channel encoded and nothing else.

There was one Woody Allen movie I ran on 35mm (Small Time Crooks) which had every digital sound format on it but sound was only in the center channel, as intended. I don't think it was ever possible to encode only certain channels on film (haven't played with any of the digital stuff so can't speak for that- but I assume they can't have matrix-encoded surround decoded from a 2-channel track?)
 

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Posted by John Wilson (Member # 269) on 04-06-2012, 08:42 PM:
 
It's possible to de-mux the audio from a 2-track file and re-configure DCP's to the correct 6-track channels...in this case track 3 which is centre and leave the rest silent, but I'd want to make sure I wasn't doing it to their copy that's for sure in case anything went astray.

But it is possible, although not sure if you can rip the audio out of an encoded file as I've not tried it.
 

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Posted by Manny Knowles (Member # 1171) on 04-06-2012, 09:26 PM:
 
This must be the season for this. Tonight I'm running a DCP of "Zoot Suit" and it's an Lt/Rt that needs to be decoded, so I had to use a patch cable to run the DSS200 audio through the DMA8plus.

Did I imagine this or did someone say there is a 650 format that will decode an Lt/Rt delivered to the Digital I/O? The only one that looked remotely correct was Format 92 or 93 (?) but it looks like that would apply SR NR. I don't need the NR. Is this a Mag format?

It would be great if rewiring wasn't necessary.
 

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Posted by Paul H. Rayton (Member # 1817) on 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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Posted by Manny Knowles (Member # 1171) on 04-06-2012, 11:03 PM:
 
Oh there was...

( ( ( ((( STEREO ))) ) ) )

...in that mix.

I tried it both ways -- Lo/Ro and decoded as Lt/Rt -- and it sounded much better decoded.

And, you're right -- Universal Studios!
 

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Posted by Aaron Garman (Member # 1653) on 04-06-2012, 11:25 PM:
 
I do laugh a bit that DCinema seems to have a harder time getting things like this right when most home cinema equipment I've used does it pretty nicely and easily. I haven't run mono on my new receiver from Pionner yet, but the previous Onkyo I had would recognize a 2.0 Dolby Digital mono track from a film and sum it to mono out of the center automatically. It was a very convenient feature.

AJG
 

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Posted by Mark Lensenmayer (Member # 134) on 04-07-2012, 04:13 PM:
 
Zoot Suit = Sensurround Plus
 

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Posted by Jonathan Goeldner (Member # 4854) on 04-07-2012, 09:11 PM:
 
for a company who can't even transfer it's catalog titles on bluray properly why does this problem not surprise me in the least.
 

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Posted by Manny Knowles (Member # 1171) on 04-08-2012, 11:59 PM:
 
The article from the link actually ends up saying that ZOOT SUIT wasn't a real Sensurround movie.

The DCP tracks exercise the subs tho. I thought it sounded great.

(BTW, there's some obvious ADR going on, so don't panic if your dialogue sometimes goes out of sync.)
 

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Posted by Lincoln Spector (Member # 6835) on 04-16-2012, 07:22 PM:
 

quote: Jesse Skeen

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I've never understood why most mono films on DVD and Blu-Ray have been done with 2-channel Dolby Digital tracks which play through the center if you have Pro-Logic enabled. A few do it correctly with just one center channel encoded and nothing else.

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