|
|
This topic comprises 5 pages: 1 2 3 4 5
|
|
Author
|
Topic: DTS:X for Cinemas
|
Harold Hallikainen
Jedi Master Film Handler
Posts: 906
From: Denver, CO, USA
Registered: Aug 2009
|
posted 04-12-2015 10:56 PM
In response to Carsten, I can't speak for my employer (USL), but I'll make a few unofficial comments. There is a real question as to what DCI will require for forensic marking. The typical forensic marking DSP will do 16 channels. As you add more channels, you can mark more (with another DSP) or not. As more and more of the audio is not marked, recovery of the forensic mark becomes more difficult. You could certainly mark every output, but it gets expensive and takes up space within the security boundary. It seems that if not all outputs need to be forensically marked, it would be possible to get more audio out of existing hardware (perhaps multiplexing additional channels onto an AES/EBU output (run 4 48k channels on a 96k output). Another thing that would help is if the forensic mark could be applied immediately after ingest (just as USL is now doing pre-rendering of object based audio). But, DCI seems to really want the forensic mark to include a time stamp, so that idea is out.
Before spending too much time and money on hardware, I think one needs to ensure there will be a bitstream that can be played. We're not allowed to talk about SMPTE meetings to the outside world, but I will say that the bitstream meetings suddenly got more interesting last week.
Personal opinions only...
Harold
| IP: Logged
|
|
|
|
Harold Hallikainen
Jedi Master Film Handler
Posts: 906
From: Denver, CO, USA
Registered: Aug 2009
|
posted 04-13-2015 02:50 PM
In my opinion, SMPTE has a ways to go. On any format, whether channel based or object based, we are relying on amplitude panning to locate sounds. The closer the speakers are together, the better it works. But, I don't think we can sense direction with the same resolution horizontally and vertically, and suspect the resolution varies as we move away from straight ahead. In object-based formats, you're free to place the speakers where you want, concentrating them where we perceive with the most resolution. With channel based, we do the same thing, but we need to match the speaker placement of the dub stage. For a presentation for Mix Magazine a few months ago, I had a graphic showing the "very talented mixer" adjusting panning controls while listening to the results on the dub stage. The speaker signals for the dub stage are recorded and sent to similarly situated speakers in the cinema auditorium. For object based sound, we do something similar. The very talented mixer listens to the sound on the dub stage and adjusts panning as required. However, in object based, instead of sending the speaker signals, we send the raw audio and the panning instructions to the cinema auditorium. There, the object renderer acts on the panning instructions to send the audio to the speakers in this auditorium. Ideally, it sounds like the dub stage.
Harold
| IP: Logged
|
|
|
|
Marcel Birgelen
Film God
Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012
|
posted 04-13-2015 04:44 PM
quote: Carsten Kurz
A standard AP20 does not have the necessary audio I/O for a decent MDA system. However, already now, multiple AP20 can be slaved.
I guess those 16 output channels should be sufficient for small rooms and maybe they could add another 16 channels not only by slaving another one but by means of an additional I/O card.
quote: Harold Hallikainen
In response to Carsten, I can't speak for my employer (USL), but I'll make a few unofficial comments. There is a real question as to what DCI will require for forensic marking. The typical forensic marking DSP will do 16 channels. As you add more channels, you can mark more (with another DSP) or not. As more and more of the audio is not marked, recovery of the forensic mark becomes more difficult. You could certainly mark every output, but it gets expensive and takes up space within the security boundary.
There isn't a whole bunch of information about how this forensic watermarking actually works, most likely on purpose.
But does it work by actively manipulating the bitstream or is it just a signal modulated on top of the bitstream? I guess it's the former, but if it is the latter one, I don't see the big deal. Then you only need to create the signal just once and adding it to the output should be a no-brainier for any DSP.
quote: Harold Hallikainen
In my opinion, SMPTE has a ways to go. On any format, whether channel based or object based, we are relying on amplitude panning to locate sounds. The closer the speakers are together, the better it works. But, I don't think we can sense direction with the same resolution horizontally and vertically, and suspect the resolution varies as we move away from straight ahead.
Hasn't it been proven in numerous experiments already, that the horizontal "resolution" is much higher than our "vertical" resolution? Then again, although we humans do have two horizontally aligned, fixed ears, our heads are not fixed on our necks. We increase our vertical spatial localization resolution (I just made this up myself) by tilting our heads.
I really hope those "speaker placement advisories" of those upcoming MDA formats increase the resolution of speakers behind the screen, because that's where it matters most. Especially on large screens, I find dialog coming elusively out of the center speaker quite annoying at times. If this would materialize, we only need the mixing folks to motivate putting the dialog where the mouth is. ![[Wink]](wink.gif)
| IP: Logged
|
|
|
|
|
|
Carsten Kurz
Film God
Posts: 4340
From: Cologne, NRW, Germany
Registered: Aug 2009
|
posted 04-14-2015 07:10 AM
The question is indeed, how much concealment the watermarking can withstand by many independent channels playing at the same time, and how often you want to have a 'marker' in the signal. In general, I would think that marking the front speakers should be enough for the purpose, as you certainly do not need a detectable watermark every few seconds.
I would think that the watermarking uses similiar techniques as used in MP3/ATRAC encoding, there is probably a psychoacoustic model being used to apply masking effects, etc. It is possible that this needs to be applied to all channels to have the best benefit from it. So, simply modulating a fixed signal will certainly not work, given also the high dynamic range/listening levels in cinema environments.
SMPTE DCPs/new KDMs allow to disable watermarking for individual channels, so that e.g. data channels, timecode, etc. for Atmos, motion seats, etc. can be left out and stay intact.
Wondering what Dolby then does within ATMOS to comply with forensic marking.
- Carsten
| IP: Logged
|
|
|
|
|
|
|
|
Bobby Henderson
"Ask me about Trajan."
Posts: 10973
From: Lawton, OK, USA
Registered: Apr 2001
|
posted 04-16-2015 09:36 PM
quote: Carsten Kurz
But that's exactly why everybody except Dolby is preferring an open standard - the standard only defines the transmission protocol for beds and objects.
Unfortunately the lack of any branding consistency, much less any consistency of how "DTS:X" or "Open MDA" or whatever the fuck it's going to be called will make any mention of it in advertising or even technical discussion absolutely WORTHLESS.
Frankly, this is even worse than THX watering down its own certification standards to allow theaters not quite compliant to still carry the logo. They're threatening to ruin DTS' Open MDA process and "DTS:X" before it can even get off the ground. Customers aren't really going to know just what the hell they're getting with this stuff. In the end the various brands will mean absolutely nothing to them on every level, even if they happen to get curious about the details.
So on top of all the stupid acronyms labeling auditoriums, signaling to the customer "it costs $3 or more dollars to enter this room," we're going to have a smorgasbord of sound formats in name only, each applying its own flavor to MDA. It will be kind of like Disney and the phony "Disney Digital 3D" thing they paste onto their movie posters.
Movie sound designers will be pulling their hair out with this because the post production mixing stage is going to end up being the only place where they can get the mix to sound as they intend. When it gets into theaters it will be screwed up in all kind of random yet "OPEN" ways.
![[Roll Eyes]](rolleyes.gif)
quote: Carsten Kurz
dts and Datasat once split in order for dts to stay in the home-cinema and licensing business, and for Datasat to take over the cinema operations. I don't think dts will re-enter the cinema business again - they will most certainly leave this part to Datasat, but will benefit from a common DTS-X implementation in the home cinema and licensing area.
Without any brand consistency between the commercial theater and home theater there will be very limited appeal for DTS:X. Right now DTS is doing alright from a perspective of branding because enough people still remember DTS as being a film sound format they experienced in real movie theaters. If DTS didn't already have its 20 years of branding history in commercial movie theaters it wouldn't stand a chance against Dolby.
My opinion is a big mistake was made when DTS spun-off its cinema division with the "Datasat" brand. There are lots of companies in existence that have totally separated businesses that still carry the same brand name. I don't know why DTS and Datasat couldn't make some kind of similar deal with the DTS brand. "Datasat" makes me think of satellite TV, satellite-based Internet service or satellite connected phones. It don't of commercial movie theaters with that brand name at all.
| IP: Logged
|
|
Marcel Birgelen
Film God
Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012
|
posted 04-17-2015 04:24 AM
quote: Bobby Henderson
Unfortunately the lack of any branding consistency, much less any consistency of how "DTS:X" or "Open MDA" or whatever the fuck it's going to be called will make any mention of it in advertising or even technical discussion absolutely WORTHLESS.
The format will be "Open MDA" and DTS:X is just an implementation of "Open MDA". This "Open MDA" thing needs a better name and a cool logo.
quote: Bobby Henderson
Frankly, this is even worse than THX watering down its own certification standards to allow theaters not quite compliant to still carry the logo. They're threatening to ruin DTS' Open MDA process and "DTS:X" before it can even get off the ground. Customers aren't really going to know just what the hell they're getting with this stuff. In the end the various brands will mean absolutely nothing to them on every level, even if they happen to get curious about the details.
Customers also don't know what they're getting with a Dolby Digital or DTS logo on the door. THX is supposed to fix that. What you want is some kind of certification.
You cannot stop competing suppliers to push their own brands and "technology", even if it's just a label on top of someone else's technology.
quote: Bobby Henderson
Movie sound designers will be pulling their hair out with this because the post production mixing stage is going to end up being the only place where they can get the mix to sound as they intend. When it gets into theaters it will be screwed up in all kind of random yet "OPEN" ways.
So, essentially, everything stays the same then? That sounds (warning: French) vaguely familiar.
quote: Bobby Henderson
Without any brand consistency between the commercial theater and home theater there will be very limited appeal for DTS:X. Right now DTS is doing alright from a perspective of branding because enough people still remember DTS as being a film sound format they experienced in real movie theaters. If DTS didn't already have its 20 years of branding history in commercial movie theaters it wouldn't stand a chance against Dolby.
I have yet to meet someone who is all excited about DTS on their home cinema set. Those people I know that care about good sound in their home theater don't prefer DTS Master Audio above Dolby TrueHD when it boils down to sound quality, as it's essentially the same. Some people are somewhat excited about Dolby Atmos, but want to wait until there are actual alternatives before buying into a single technology. They all expect those future AVRs to support all comon MDA formats.
quote: Bobby Henderson
My opinion is a big mistake was made when DTS spun-off its cinema division with the "Datasat" brand. There are lots of companies in existence that have totally separated businesses that still carry the same brand name. I don't know why DTS and Datasat couldn't make some kind of similar deal with the DTS brand. "Datasat" makes me think of satellite TV, satellite-based Internet service or satellite connected phones. It don't of commercial movie theaters with that brand name at all.
Well, their sister organization, Datasat Communications is actually all about satellite communications .
DTS was already failing as a brand in the last years of the "Digital on Film" market, Dolby clearly won the race with its ubiqutous SRD and they clearly made an impact on the home theater market too. For DTS as a format, there was nothing to be gained in D-Cinema, just like Dolby Digital became redundant. They clearly focussed on the DVD to Blu-Ray transition and won the battle there as the leading HD audio format. Them spinning off their hardware and "Digital on Film" division makes sense to me. It also makes sense to give it another name, if DTS will only be one of the technologies you'll support in your product portfolio.
Right now, Datasat is a strong brand in both cinema and high-end home cinema. Doing the same with the DTS brand name would have been a whole lot more confusing. Also, consider your market here: Most of your customers are people who know what they're buying.
| IP: Logged
|
|
|
|
|
|
|
|
All times are Central (GMT -6:00)
|
This topic comprises 5 pages: 1 2 3 4 5
|
Powered by Infopop Corporation
UBB.classicTM
6.3.1.2
The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion
and agrees to release the authors from any and all liability.
|
Home
![[Confused]](confused.gif)
Printer-friendly view of this topic