Dolby Atmos Theatre System - Page 6 - AVS Forum
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Old 04-28-2012, 10:42 AM
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Quote:
Originally Posted by Gary J View Post

Well that is unfortunate. I think there are many dipole and bipole speakers in use in HTs for exactly the reason highlighted. I still think they a good alternative to a proliferation of speakers. Some petty poster may not want to hear that - too bad.

We're talking theatrical audio here... there really is no reason to use dipoles for the reasons GXM listed...

If we're talking about HT, they have a place in the discussion..

But we're not.
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Old 04-28-2012, 10:44 AM
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Originally Posted by markus767 View Post

I did not say it necessarily would hamper the results. I said it could if the old content creation process is kept and the end result is still a 7.1 mix with some additional buzzing bees flying around behind your back.

Markus.. I know I keep bringing this point up, but I really feel that because we are still dealing with a flat 2D image that the bed + object based paradigm is the best choice... I truly don't believe that a fully object based workflow is desirable or necessary as long as a heads are forced to face straight ahead to tie the sound with the image..
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Old 04-28-2012, 11:37 AM
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Quote:
Originally Posted by GXMnow View Post

Here is where this claim comes from. May not be straight from someone at SRS MDA (DTS) but obviously someone is trying to stir the pot. I am not Saying ATMOS is the perfect end all be all ever in sound, but... check out this blog article.

http://blog.mixonline.com/mixblog/20...ation-systems/

Those are quite a bit of claims... I was surprised to read it and see what they, whoever they are, claim.... same response that Roger has....

OMG...
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Old 04-28-2012, 01:33 PM
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Originally Posted by FilmMixer View Post

Those are quite a bit of claims... I was surprised to read it and see what they, whoever they are, claim.... same response that Roger has....

OMG...

FlimMixer you have a PM.

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Old 04-28-2012, 02:11 PM
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I just watched the Stuart Bowling video. Lots of talk about precision wrt objects panning. I suppose that the earlier thinking that surround fields should be diffuse so as to not pull the moviegoers' attention from the story on the screen is out the window?

Just askin'.

Jeff
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Old 04-28-2012, 02:43 PM
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Quote:
Originally Posted by pepar View Post

I just watched the Stuart Bowling video. Lots of talk about precision wrt objects panning. I suppose that the earlier thinking that surround fields should be diffuse so as to not pull the moviegoers' attention from the story on the screen is out the window?

Just askin'.

Jeff

You can difuse sounds by using the surround panners divergence control and assigning across more than one speaker.

However you lost the ability to have pinpoint accuracy when you start talking about dipole, etc.
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Old 04-28-2012, 03:25 PM
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It makes mores sense that we have monopole surrounds, and mixers mix accordingly with respect to adjusting the wetness of each element according to where it should be. This would work best if monopoles were the standard as dipoles in this scheme would make everything more diffuse than was intended.

Jeff
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Old 04-28-2012, 04:10 PM
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Quote:
Originally Posted by pepar View Post

It makes mores sense that we have monopole surrounds, and mixers mix accordingly with respect to adjusting the wetness of each element according to where it should be. This would work best if monopoles were the standard as dipoles in this scheme would make everything more diffuse than was intended.

Jeff

Monopoles are the standard.

Not directed at you Jeff, but I think we all should be mindful to keep this discussion on topic which is Dolby Atmos for D-Cinema.

It would be a shame to devolve into a thread about what it isn't or what it should be when and if it ever becomes a home technology.
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Old 04-28-2012, 04:45 PM
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Quote:
Originally Posted by GXMnow View Post

[. . .] Getting the ATMOS data onto a Blu Ray is another discussion.

Ok, so no discounted "home" Dolby Atmos surround decoders in the stores for Black Friday 2012!

But there are still some short term Home Theater gains possible...

With only a small number of Dolby Atmos "64.x" capable theaters available this year, I'm assuming studios that mix a movie (once!) in Dolby Atmos objects will also use an associated rendering mechanism to produce PCM stem sets for all of the other theatrical audio formats in which they intend to distribute the movie, e.g., 2.0, 5.1, 7.1, SDDS, IMAX, etc., "to get the best possible mix" for each speaker configuration...

And I'm guessing the same technology would let the studios render PCM stem sets for 5.1|7.1 plus Front_Heights|Front_Wides|Front_Heights+Front_Wides. The PCM stem sets of these mixes could then be 'reprocessed' through either of the "mythical" DPLIIz or DTS Neo:X "near discrete quality" matrix encoders to create a 7.1 BD soundtrack which is 'content optimized' for (in AVR) post processor expansion|extraction of height and|or wide channel content to allow "near discrete quality" 9.1|11.1 playback. All possible with just Dolby Atmos plus existing, 'in place' technology!

[I won't hold my breath! ]

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Old 04-28-2012, 10:18 PM - Thread Starter
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Quote:
Originally Posted by SoundChex View Post

[i]With only a small number of Dolby Atmos "64.x" capable theaters available this year, I'm assuming studios that mix a movie (once!) in Dolby Atmos objects will also use an associated rendering mechanism to produce PCM stem sets for all of the other theatrical audio formats in which they intend to distribute the movie, e.g., 2.0, 5.1, 7.1, SDDS, IMAX, etc., "to get the best possible mix" for each speaker configuration...

That would be the fastest way. I expect it will take some time to build a level of trust that a rendering algorithm can replace crafting each mix. However, I expect time will prove it is possible, and with the ability to hand tune tweaks along the way if needed, it will quickly become the norm workflow. Mix once, render many.

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And I'm guessing the same technology would let the studios render PCM stem sets for 5.1|7.1 plus Front_Heights|Front_Wides|Front_Heights+Front_Wides.

Yes.

Quote:


The PCM stem sets of these mixes could then be 'reprocessed' through either of the "mythical" DPLIIz or DTS Neo:X "near discrete quality" matrix encoders to create a 7.1 BD soundtrack which is 'content optimized' for (in AVR) post processor expansion|extraction of height and|or wide channel content to allow "near discrete quality" 9.1|11.1 playback. All possible with just Dolby Atmos plus existing, 'in place' technology!

While technically possible, I do not see it happening that way. PLIIz and Neo:X use completely different encoding, so it would not be possible to make one 5.1 or 7.1 track that satisfies both.

The native render of a 3D object-based mix to 5.1 (or 7.1) delivery formats will work about as well as any other 5.1 mix, so it will not degrade the PLIIz or Neo:X result, it just won't help height cues in any particular way either.

One area it will make an improvement is in PLIIx compatibility for 5.1 content. Right now, when 7.1 content is downmixed to 5.1 the rear surround pair is folded into the side surround pair. This erases any ability for a decoder to discern the rear from the side signals.

Ideally the Lsr and Rsr signals would be encoded so that a PLIIx decoder could extract them to the correct rear speakers. That's exactly how MDA rendering works, since it's a natural result of VBAP panning. I presume the same is true for Atmos.

To the extent PLIIz and Neo:X work the same as PLIIx, then at least there's some benefit coming their way.

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Old 05-01-2012, 01:41 AM - Thread Starter
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Originally Posted by pokekevin View Post

Wonder what awesome name dts will call it! We all know dts is better

Just thinking about the tiny pinpoint sounds that audio objects can deliver, how about DTS Atoms?

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Old 05-01-2012, 01:51 AM - Thread Starter
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Originally Posted by pokekevin View Post

Huh?

Sorry I missed your question. I was saying that once audio is described as sounds at positions in space, the way it is mapped to speakers can be decided based on other criteria, such as number of speakers available, the size of the audience or sweet spot, the directional accuracy required, etc. I mentioned "conventional" x-y panning expanded to add z: VBAP, WFS, and Ambisonics (or High Order Ambisonics). Each has its own strengths and weaknesses.

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Old 05-01-2012, 03:01 PM
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Something of this nature will take time to trickle down to the consumer world. First there has to be a body of work consumers can acquire and second Dolby will need to get chip sets out to handle the metadata in the "typical" consumer's playback space and third there has to be changes to compensate for the difference in speaker/seat distances differences. Exciting, none-the-less.

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Old 05-01-2012, 05:04 PM - Thread Starter
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Originally Posted by Dennis Erskine View Post

Something of this nature will take time to trickle down to the consumer world. First there has to be a body of work consumers can acquire and second Dolby will need to get chip sets out to handle the metadata in the "typical" consumer's playback space and third there has to be changes to compensate for the difference in speaker/seat distances differences. Exciting, none-the-less.

Yes to all, but let me comment on the third one. What is great about the object-based playback (i.e., rendering) is that it works with any speaker configuration file. Just load in the locations (which can be automatic as done in Trinnov), and it renders correctly. Every home could have different speaker coordinates (and MLP target), but the renderer is fine with any. And very easy to support multiple LPs if desired.

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Old 05-01-2012, 05:45 PM
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From The Hollywood Reporter article Peter Jackson Considering Dolby Atmos for 'The Hobbit' (link):
Quote:


The new Dolby sound format will be installed at the Dolby Theatre, home of the Academy Awards
[. . .]
On Tuesday, the company revealed that the home of the Academy Awards at Hollywood & Highland will be rebranded the Dolby Theatre and that the venue would be upgraded to support Dolby Atmos.


And no doubt Auro-3D will be banned from the building.
Quote:


Disney/Pixar's Brave will be the first film to test the Atmos format, and Dolby aims to install the sound system in 10-15 theaters worldwide for this trial run.


10 theaters 'down' . . . (approx) 149,990 theaters (worldwide) still to be converted...
Quote:


Dolby indicated that after a cinema launch, the longer term goal is to bring an Atmos experience to the living room, including on tablets, PCs and mobile devices.


I'm assuming "a limited feature set only" for the tablet when compared to a regular movie theater!

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Old 05-01-2012, 06:01 PM
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Wonder what Atmos will do to ticket prices?

Any speculation on that, Roger?

Jeff
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Old 05-01-2012, 06:43 PM
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Quote:
Originally Posted by pepar View Post

Wonder what Atmos will do to ticket prices?

Any speculation on that, Roger?

Jeff

Not Roger...but I simply could not resist.

Perhaps they will ascend into the Atmosphere?

Bwa-ha-ha!
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Old 05-01-2012, 07:23 PM
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Dolby aims to install the sound system in 10-15 theaters worldwide for this trial run.

I hope Dolby publishes a list of those theatres when 'Brave' is released.

Sanjay
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Old 05-01-2012, 09:45 PM - Thread Starter
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Quote:
Originally Posted by pepar View Post

Wonder what Atmos will do to ticket prices?

Any speculation on that, Roger?

Yes indeed. Post #69.

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Old 05-01-2012, 11:15 PM
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I'm surprised no one has mentioned what seems to be a strong similarity to Trinnov, which also aims to reproduce a soundfield, not channels.

As far as adoption, given the paltry number of even 7.1 soundtracks, why would it be expected that filmmakers would be more enthusiastic about Atmos?

Noah
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Old 05-02-2012, 12:52 AM
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Originally Posted by noah katz View Post

I'm surprised no one has mentioned what seems to be a strong similarity to Trinnov, which also aims to reproduce a soundfield, not channels.

That's because they aren't similar: one is an object-based mixing/rendering system while the other is room correction.

Sanjay
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Old 05-02-2012, 01:28 AM
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Quote:
Originally Posted by SoundChex View Post

From The Hollywood Reporter article Peter Jackson Considering Dolby Atmos for 'The Hobbit' (link):
And no doubt Auro-3D will be banned from the building.

10 theaters 'down' . . . (approx) 149,990 theaters (worldwide) still to be converted...

I'm assuming "a limited feature set only" for the tablet when compared to a regular movie theater!

Its not at all surprising about "The Hobbit..."

If you watched the videos on Dolby's site, some of the mixers talking up the tech were from Park Road post.

The comment about the Dolby Theater is strange.

They have never screened films in that room, nor is it in any way a proper venue to screen then if they wanted to... its now the home of a Cirque De Soleil show except for 8 weeks around the Oscars.

I suspect they meant to say they will be installing the system in the Academy's theater... which is located inside the Academy's headquarters.

I'll see if I can get clarity on that.
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Old 05-02-2012, 01:31 AM
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Originally Posted by sdurani View Post

I hope Dolby publishes a list of those theatres when 'Brave' is released.

I know where one of them will be.

Don't I owe you a lunch by my place sometime soon?
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Old 05-02-2012, 01:40 AM - Thread Starter
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Quote:
Originally Posted by noah katz View Post

I'm surprised no one has mentioned what seems to be a strong similarity to Trinnov, which also aims to reproduce a soundfield, not channels.

Not really the same thing, though, in my understanding.

First, there is no Trinnov encoder. Instead, it relies on comparing the user-selected "ideal" speaker positions for 2.0, 5.1, or 7.1 systems (from a menu) against the actual speaker positions of the system.

If the actual speakers are in the same locations as in the user selected layout menu, the amount of processing Trinnov applies is minimal. As it should be.

If the actual speakers are in non-standard locations, Trinnov will work its magic to represent the original soundfield.

You may say good, instead of mapping the soundfield relative to a static notion of ITU 5.1, let the source bitstream dynamically move those "speakers" in 3D space, and then Trinnov will make it happen for the listener. That brings us back to "there's no encoder." And if you devised one, I'd wager it would look a lot like an object-based system.

So what we're coming down to then is the question of rendering. Object based sounds can be rendered in different ways, such as panning, Ambisonics (or, more generically, high order spherical harmonics), or wave field synthesis. Each of these techniques can be degraded by a poor choice of speaker positions, and to the extent that a Trinnov-like process can mask those imperfections, it could potentially enhance the final performance of these renderers. But my feeble brain cannot see how it could be used instead of them.

Regardless of what may theoretically be possible with Trinnov technology, I think it is fair to say that as it stands today it cannot just slide into a similar role as the other 3D formats already on the table.

[ETA: I wish I would have waited until I saw Sanjay's post. Would have saved me some head scratching! ]

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As far as adoption, given the paltry number of even 7.1 soundtracks, why would it be expected that filmmakers would be more enthusiastic about Atmos?

5.1-->7.1, modest change. 5.1-->40.1, big change. More fun. More room for artistic expression.

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Old 05-02-2012, 02:17 AM
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Originally Posted by FilmMixer View Post

Don't I owe you a lunch by my place sometime soon?

Maybe you can pack that lunch to go and we'll hit the road looking for Trainotti in the witness relocation program or where ever he disappeared to. You're also past due on a meet for our local HT group; good opportunity to explain/discuss upcoming changes (e.g., object based mixing) to your profession.

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Old 05-02-2012, 02:38 AM
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Quote:
Originally Posted by sdurani View Post

That's because they aren't similar: one is an object-based mixing/rendering system while the other is room correction.

Trinnov is capable of remapping channels to non-standard speaker positions. It's also capable of finding the location of speakers within the room.
Similar techniques could be used for rendering Atmos streams and finding speaker locations.

Markus

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Old 05-02-2012, 06:59 AM
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As I understand them ... and that understanding could be faulty ... Trinnov can move perceived speaker locations while Atmos adapts the mix to the speaker configuration so that object placement is as was intended by the mixer.

... yeah, you're speculation seems plausible ...

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Old 05-02-2012, 01:03 PM
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Quote:
Originally Posted by markus767 View Post

Similar techniques could be used for rendering Atmos streams and finding speaker locations.

Trinnov leaks all the information in an entire channel into a second speaker in order to create a phantom image (virtual speaker) at an ITU location. By comparison, Atmos is rendering individual sounds (excepting channel beds) to a variety of speaker layouts. It's mapping content rather than re-mapping whole channels. Trinnov is room correction; aside from correcting for distance (using levels and delay, which all room corrections do), Trinnov also corrects for angle (which makes them unique). But I don't see that as similar to object based mixing and rendering.

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Old 05-02-2012, 02:01 PM - Thread Starter
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Quote:
Originally Posted by sdurani View Post

Trinnov leaks all the information in an entire channel into a second speaker in order to create a phantom image (virtual speaker) at an ITU location.

I think it would be more accurate to say it leaks an entire channel to every other speaker to build the originally intended soundfield. In this respect it is a lot like Ambisonics, and more particularly high order spherical harmonics. Their AES paper states:
Quote:


Selecting the optimal spatial resolution (order L)
The maximal order L depends on the loudspeaker
layout. For example, second order is sufficient for
standard stereo, but 5th order is required in order
to take advantage of the 5.0 layout.

In such systems, the signals come from all the speakers, at particular gains and polarities to reconstruct the soundfield. The higher the order, the larger the sweet spot.

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Originally Posted by pepar View Post

As I understand them ... and that understanding could be faulty ... Trinnov can move perceived speaker locations while Atmos adapts the mix to the speaker configuration so that object placement is as was intended by the mixer.

... yeah, you're speculation seems plausible ...

Trinnov can move a "speaker" location, but that is a static positional offset. It requires a lot of calculation to determine these 5th-order filter coefficients that create the effect. If it were confronted with moving that virtual source location on a dynamic basis, it would have to complete those calculations in a span of, say, 5 ms, and do so 200 times per second as the program plays. And not just for 7 sounds (speakers), but for every individual sound object in the program. GXMnow mentioned 7.1 bed channels and 16 objects for the Atmos demo mix. That alone is 3x the number of sources Trinnov supports today. Couple that with the dynamic aspect I already mentioned, and it's probably safe to say this is well beyond the realm of practicality for Trinnov as it is currently designed.

To the extent that imm Sound has a working system based on some form of soundfield reconstruction, that at least proves such things can be done, given efficient computational techniques such as described in their paper:
Quote:


ACOUSTICS2008/2934
Real-time 3D audio for digital cinema

We present a real-time 3D audio system with a number of nice features: it is suited for plausible reference with the visual environment, it is real-time capable, it can process multiple moving sound sources and listeners in a normal CPU. In our approach, a database of pressure and velocities impulse-responses (IRs) is computed offline for each (architectural) environment using physically based ray-tracing techniques. During playback, the real-time system retrieves IRs corresponding to the sources and target positions, performs a low-latency partitioned convolution and smoothes IR transitions with cross-fades.


Deadwood Atmos theater
AV7702 Atmos 7.4.4, SSP-800 PLIIx 7.4
Aerial Acoustics 7B/CC3B fronts, B&W CWM8180 surrounds, Tannoy Di6 DC heights, Hsu ULS-15 subs
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Old 05-02-2012, 06:27 PM
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Would it be accurate to describe Atmos as almost like a 'resolution enhancement' in terms of sound spacialization? As in, a helicopter sound has to move from the front of the room to the back. Atmos can do it with a standard 5.1 configuration, or it could take advantage of 16 speakers along the ceiling by moving the same sound through those speakers... So it just increases the 'resolution' of the sound panning front to back by using more speakers to fill out the movement, like more pixels in a television...
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