Descriptive Audio

[Brandon Wood]

Hi all, My wife is a teacher of the blind and visually impaired and brought up the idea of doing a private screening at our small theater for her students. Basically we would want the descriptive audio track to play through the main speakers rather than through the headphones. Do you all think this is even possible? Assuming the DCP has a VI track, would it be possible to somehow get that to play on the main speakers? We have a CP650 if that helps.

Also, anybody have any thoughts on non-Disney films with VI tracks that would be good/appropriate for middle and high school kids? I'm also not opposed to making a DCP from a Blu-ray, but I'm not sure which movies have descriptive audio tracks. Thanks for your time!

[James Gardiner]

There are two possible options.

However, please be aware that both options require changes to the base configuration of either the player or the sound processor.

1. DCI Player
   The DCI player typically allows audio channel mapping. For example, you could replace the surround channels with the HI track, rather than mixing the HI track into them.
2. Sound Processor
   The sound processor can typically map input tracks to different outputs, similar to the player. However, it can also commonly mix a single input track into multiple output channels. For example, you could mix the HI track into the front speakers while keeping the original Left, Centre, and Right audio present.

Important: This usually requires manually changing the base configuration. After the event, the configuration will need to be changed back. This type of setup generally cannot be saved as an optional channel selection.

[Leo Enticknap]

The CP650 does not process the HI and VI channels from AES channels 7 and 8 at all. Assuming that this one receives AES3 audio from the DCP server via a cat790 option card, your only DCP option is format 88, which hard routes channels 1 through 6 from the DCP to their ISDCF channel outputs. The CP650 does generate a HI channel, but this is a mixdown of the stage channel outputs, not a passthrough of channel 7 on the DCP.

So in a CP650 setup, the HI and VI channels are being routed to the headsets likely in one of two ways. Either a DolReMi server is in use with a Fidelio/Captiview system, which transmits the audio digitally to a receiver with a DAC in it that connects to the customer's headset, or another system is in use (e.g. the USL/QSC/MiT IRC emitter) that receives the HI and VI tracks in analog form, with a totally separate DAC sitting between the AES3 output for that pair and the analog input to the emitter.

If Brandon has the Fidelio/Captiview system, I'm afraid that there is no easy way to send the VI audio to somewhere other than the headsets. The least disruptive way would likely be to use a separate DAC (something like this) with whatever adapter and bespoke cables are needed to get the signal out of the DCP server. When I've had to resort to these setups and the AES3 output from the server is 2 x RJ45s, I've tended to route HI and VI to channels 15 and 16, then make up an RJ45 to BNC or RCA cable connecting just that pair. The RJ45 connection for 1 through 8 remains untouched and goes to the audio processor; and if it is a 7.1 house, the rear surrounds routed to 7 and 8.

For what Brandon is trying to achieve, I would then take the VI analog out from the DAC straight in to the power amp channel(s) for where the VI audio is desired - side surrounds, maybe. If Brandon already has such a DAC in place to feed an emitter/transmitter with analog inputs (i.e. he is not currently using Fidelio/Captiview), then all that would be needed is this final step of rewiring that channel to the desired power amp channels.

[Gordon McLeod]

One way is to change the channel mapping in the server for that one event

[Leo Enticknap]

I guess I was slightly overthinking the problem. However, if the server is a Dolby DSS, this isn't an option (because they don't allow channel mapping: channel1 on the DCP is hard coded to AES3 channel 1 out, etc.). If that is an option, gains will likely have to be adjusted in the CP650 or power amps to make the VI commentary audible. Replacing the center channel with VI won't work, because the VI commentary assumes that the listener has good hearing, and can therefore hear the movie's dialogue unaided: it just describes what cannot be understood from the movie's soundtrack alone, if you were in the theater with your eyes closed. So the center channel on the DCP would have to be played, thereby making the side surrounds the obvious candidate to route the VI channel to. In order for the commentary to be comfortably audible, the gain on all the other channels apart from center would likely have to be knocked down significantly.

If Brandon wants to try this, I would strongly suggest doing some test listens before running an actual show this way, in order to find the optimal channel gain settings. And obviously, note what they were before making any changes, in order to be able to reset anything afterwards. One way to do this would be to download a settings backup from the CP650 before you start, and put it back again after the special show.

[Harold Hallikainen]

Of course it does not help here, but the JSD-60 would let you mix VI into any output channel (assuming the auditorium is 5.1 since the JSD-60 only has 8 input channels).

[Brandon Wood]

Our server is a DSS200, and we do use a QSC transmitter for HI and VI. I suppose the absolute easiest option would be to find a Blu-ray with descriptive audio and play it that way (or rip it and make a DCP), though I wonder if we'd need to license that specific track or just the title.

[Leo Enticknap]

Sorry to be the bringer of bad news, but the server being a DSS200 rules out a DCP playback solution that doesn't involve rolling up your sleeves and diving into the back of the rack. It can't do channel mapping/routing.

If you can find a BD of the movie that has a VI descriptive audio track on it, rip it, and make a DCP from it that replaces the side surround channels with the VI channel, then with a few tweaks to the gains either in the CP650 or at the power amps, the job is done.

If you have to take AES channel 8 (the VI channel) from the DSS200's cat862 media block to the power amps for the side surrounds, the easiest way I can think of would be to install a signal cable directly from the channel 2 input on the Phoenix connector of the USL/QSC/MiT IRC-28C emitter to the power amps for the side surrounds, and to temporarily disconnect the channels 5 and 6 inputs to those amps for the duration of the show.

[Jason Sharp]

You could pin out a custom audio cable to use between the DSS200 and CP650 to use during these special VI shows.

[James Gardiner]

I am going to have to say it. If your still using a DSS200, or a CP650. I would really take a look at your business model in the coming years. I know its hard out there. But seriously... At some point respect your audiance and upgrade your equipment.

I am occationally watching session at some older independants with 14year old projectors with fuzzy and dim images on screen because the light engines are done. the air filtration in those old light engins is non existant, small particulates form a residue on the optical surfaces, dropping lights levels below 48nits (14fl) and introducing a fuzzy feel, less scrip image.

I know its a difficult time to purchase, but at some point...

[Marcel Birgelen]

If you have a decent source for those movies, I think the most reliable result would be by creating your own DCPs. The channel mixing is something that could be semi-automated using something like ffmpeg, if you don't want to load the entire movie into an editor.

It's unclear how you're related to the cinema operator, but if you're not directly related, then it's often difficult to make the correct arrangements with the cinema for such special requests, and that's why I'd prefer coming prepared with something they should be able to handle out-of-the-box.

[Brandon Wood]

I am going to have to say it. If your still using a DSS200, or a CP650. I would really take a look at your business model in the coming years. I know its hard out there. But seriously... At some point respect your audiance and upgrade your equipment.

I am occationally watching session at some older independants with 14year old projectors with fuzzy and dim images on screen because the light engines are done. the air filtration in those old light engins is non existant, small particulates form a residue on the optical surfaces, dropping lights levels below 48nits (14fl) and introducing a fuzzy feel, less scrip image.

I know its a difficult time to purchase, but at some point...

I'm going to have to say it: the general audience does not care about these things (up to a certain point, at least). They are happy to come to our small indie theater and understand we're doing our best, and our Series 1 projector still looks good and our sound is good. I don't really appreciate the insinuation that we don't respect our audience. To give you more context, we are a tiny nonprofit that purchased a theater that was not well taken care of by the previous owner (they basically ran it as a hobby), and are in a very slow process of fundraising and doing a complete renovation (this includes equipment upgrades). Until that happens, though, we are stuck with the equipment that was already there. Not to mention right now we aren't even playing first-run films.

Sure, I get it, most of the people on here (this includes myself, by the way) would want the best 4K laser projection and Dolby Atmos sound, but that's just not realistic for most indie theaters.

[Leo Enticknap]

I no longer look after any Series 1 projectors among my regular customers, but I have many very early (as in, manufactured 2010 to '12) Series 2s, DSS servers, and CP650s. I completely agree with Brandon: none of the owners of this equipment disrespect their audience. They simply cannot afford to replace their projectors and audio gear with brand new (banks will not lend to smaller chains and indies to do this, because they can see that, thanks to the current state of the movie industry, doing so would be too high risk, given the depreciation cycle of what those loans would be used to buy), and so the options are keeping the older stuff on life support for as long as possible, or closing down. I am about to start a backplane replacement on a DP2K-32B manufactured in June 2010 and with 120K card cage hours on the clock in one of these theaters.

Returning to the thread topic, the bottom line is that there are a number of ways to achieve what Brandon is trying to do. IMHO, the easiest and least disruptive would be to take some signal wire, connect one end to the VI input on the Phoenix connector on the back of the existing HI/VI/CCAP emitter, and hook the other end directly to the power amp channels for the side surrounds. That would give you channel 8 in the auditorium. Even cleaner would be if you can find where the existing cable originates in the booth (I would guess that there is a DAC for the 7/8 AES3 pair), and tap it there.

[Marcel Birgelen]

It wasn't clear to me Brandon is actively involved in running the place. I still retain my position about creating dedicated DCPs where possible, since this doesn't require any change to the existing setup.

I guess that most people that give about cinema would love to run the best gear out there. Unfortunately, reality is imperfect... back in the film days, a 14 year old projector would qualify as "barely used" or "brand new"... And the CP650, while old, does the job and is cheap to replace if anything breaks. Personally, I favor a "well maintained ghetto setup" versus a 13-in-a-dozen but shiny and new multiplex setup.

If you have a secondary sound system, like a PA system for live performances, you could easily route the audio descriptions via that route. You want to have some control with regards to the volume of those tracks v.s. the rest of the sound track.

[James Gardiner]

In my own defense, I have been visiting some independent theater locations lately. It breaks my heart when I see a 12-to-14-year-old light engine struggling to project a decent image. Yes, it still turns on, but the picture quality is severely compromised.
Over years of operation, the cooling system pulls air straight through the light engine, coating the prism optics in fine particulates. This results in reduced light output, compressed contrast, and a blurry,glowing image. Yes, most patrons may not notice the difference, but just like the old days when lamps were pushed far beyond their intended lifespan to save costs, I believe this behavior hurts our industry more than it helps. If you are running a Dolby DSS200, you likely also have a projector from that era—and seeing them neglected like this really frustrates me.