KeithL
Administrator 
Posts: 10,273
|
Post by KeithL on Jun 7, 2018 11:13:25 GMT -5
In its full "conceptual" description, an Atmos decoder should be able to work with an arbitrary number of speakers located at fully arbitrary positions. (This is the way it was described in the beginning.)
However, from a practical point of view, this is problematic.
First off, it requires a lot more processing power and programming complexity to deal with arbitrary locations than with a set of fixed options... even if you offer lots of options.
Second, it requires a level of validation and limitation.... you simply cannot have a system that works with fully arbitrary positions. If you can figure out the math that will allow you to produce enveloping surround sound using ten speakers, ALL ON THE LEFT SIDE OF THE ROOM, you will be rich. In the mean time, any attempt at allowing "arbitrary speaker positions" is going to require some sort of validation ("you can put the speakers wherever you want - then we'll tell you if your choice will work or not").
Third, because people are familiar with the customary locations, it's simpler to describe things in terms which people are familiar with.
(And, as part of that, since Atmos does include bed channels, which are supposed to have fixed locations anyway, you can only offer fully arbitrary positions for extra channels - beyond those - anyway.
The theater system may allow a lot of arbitrary object speakers, but it still expects each of the bed areas to be "populated" with one or more speaker. )
Arguably, Atmos COULD be made to work with fully arbitrary speaker locations, but the results with some choices would be awful... so it does make sense to limit them.
Right, it is not a matrix, but the metadata should not call out a specific speaker to play the object sound from (ie DD 5.1 has each specific sound tided to one specific channel), where with Atmos the OAR takes the data and computes which speaker to play out of. It is just similar to a matrix that would take sounds and try to interpret where they should go then place the sound on those specific channels. Atmos is superior in the sense that the OAR does not have to interpret where the sound should come from (it is given that XYZ data from the metadata) it just has to place that sound based on the specific speaker layout of your room. In theory Atmos should make setting up your HT easier since now you would have some flexibility in speaker placement if your room limited you to having speakers in the precise perfect location. The OAR would recognize where your speakers are after calibration and then place the object audio in the right combination of channels to best reproduce the intended sound. Strangely , dolby still has very definite speaker postitions and the direction they should face. I am talking real atmos not some sound bar/bouncy shite . |
|
|
|
Post by Casey Leedom on Jun 7, 2018 11:26:48 GMT -5
KeithL, will the RMC-1 be able to do all the Atmos Coolness that you describe with a 5.1 Speaker setup? That is, do it's best to "render" the (X, Y, Z) objects into the 5.1 Speakers? And I guess the same question goes for 7.1 Soundtracks: will the RMC-1 map the Left/Right Rear Speakers of a Lossless Dolby 7.1 Soundtrack to the Left/Right Surround Speakers? Casey
|
|
|
|
Post by davidl81 on Jun 7, 2018 11:38:39 GMT -5
In its full "conceptual" description, an Atmos decoder should be able to work with an arbitrary number of speakers located at fully arbitrary positions. (This is the way it was described in the beginning.)
However, from a practical point of view, this is problematic.
First off, it requires a lot more processing power and programming complexity to deal with arbitrary locations than with a set of fixed options... even if you offer lots of options.
Second, it requires a level of validation and limitation.... you simply cannot have a system that works with fully arbitrary positions. If you can figure out the math that will allow you to produce enveloping surround sound using ten speakers, ALL ON THE LEFT SIDE OF THE ROOM, you will be rich. In the mean time, any attempt at allowing "arbitrary speaker positions" is going to require some sort of validation ("you can put the speakers wherever you want - then we'll tell you if your choice will work or not").
Third, because people are familiar with the customary locations, it's simpler to describe things in terms which people are familiar with.
(And, as part of that, since Atmos does include bed channels, which are supposed to have fixed locations anyway, you can only offer fully arbitrary positions for extra channels - beyond those - anyway.
The theater system may allow a lot of arbitrary object speakers, but it still expects each of the bed areas to be "populated" with one or more speaker. )
Arguably, Atmos COULD be made to work with fully arbitrary speaker locations, but the results with some choices would be awful... so it does make sense to limit them.
Strangely , dolby still has very definite speaker postitions and the direction they should face. I am talking real atmos not some sound bar/bouncy shite . Yes with "bed channels" are still fixed and should be in the same placement as a standard 7.1 system. I was speaking more to the over head channels as there can be some variance in their placement. Of course nothing extreme as all of them on one side of the room, but more to the fact that if the LF speaker is not exactly 2.5' in front and 1.5' to the left of the primary seating position then the sound is distorted. The Atmos system should in theory be able to adjust the sound based on actual speaker placement. Now I do agree that processor power comes into play and maybe that is why we are seeing 7.1.4 labels. If the soundtrack is just broken in channels then the AVR does not have to do as much work, all it has to do is give a preset sound to each preset speaker. In theory a less powerful (cheaper) processor would be needed thus lower priced AVR's could support Atmos. Now if I could just get to test the RMC-1 I will install two extra in ceiling speakers and personally test if sound is coming from either 4 or 6 speakers, I would be doing this for the good of the board, since I am a stand up kinda guy. I am wondering though if 7.1 is used as the base layer for Atmos then a true 9.1.6 setup may never happen. The .6 could all play since they are objects, but most likely only 7 of the 9 speakers would get used since they are base layers. If any sound were to come out of the other 2 "main" speakers I would assume it would be very minor. |
|
KeithL
Administrator
Posts: 10,273
|
Post by KeithL on Jun 7, 2018 11:56:07 GMT -5
The problem is that we have sunk into a mire of semantics.....
The discs in question are NOT "7.1.4 discs" - at least not if they are actual Atmos discs - regardless of what they may say on the label. (According to the way Dolby describes the numbering convention, you may have a 7.1.4 SYSTEM, but there is no such thing as "a 7.1.4 Atmos disc". However, you most certainly could have "a disc that was mixed such that the mix is optimized for playback on 7.1.4 systems". )
What those discs are is "discs that have been encoded in such a way that they have four fixed height objects which are immovably mapped to the typical locations of four height speakers".
(In Dolby Atmos, objects CAN move and change size, but you CAN simply park them somewhere and never move them if you choose to.)
In a practical listening environment, we would expect channels that are mapped to physical speaker locations to work best..... If you have four fixed location height objects, mapped to the typical locations of four height speakers, when you play them with four height speakers, each object will correspond to a physical speaker. But, if you play that same mix on six height speakers, each of those object locations will fall between two of your six height speakers (so each is now positioned at a "phantom center speaker" instead of a physical speaker). In a perfect world there would be no difference. However, in the real world, I would expect more pinpoint imaging from a physical speaker than from a virtual source location.
Therefore, a mix created with four fixed-point objects may in fact sound better on a system with four height speakers than with four.
HOWEVER, note that this is a special case... and a subset of what Atmos itself is capable of.
In a "normal Atmos mix" objects move around between the speakers, which makes the specific location of any particular speaker less significant.
(But, yes, if most discs end up being encoded this way, then those discs may sound best on systems with four height speakers, and only "full on Atmos discs" may benefit from having six height speakers.)
If you want to look at that in a negative light then: - They are discs that have been encoded in such a way that they fail to take advantage of all the features and capabilities of Dolby Atmos.
- This may have been done because they were mixed and encoded using software with limited capabilities. (I'm told only a few studios are actually equipped to master Atmos properly). - It may have been done because the engineer simply was too lazy to do it right. (The budget to re-master old movies, or low cost productions, for home use is often limited.)
- It may have been done because of limitations in the original content. (In order to use separate objects, you must have each sound you want to make into an object on its own separate track, doing this after the fact is very difficult.)
If you want to look at it in a positive light then: - Perhaps, recognizing that almost nobody uses six height speakers, they have optimized the mix to work better with more typical systems that use two or four height speakers. - (You could split the difference and suggest that they chose not to expend extra effort to improve how the mix would sound on the few home systems that actually have six height speakers.)
The bottom line is that this is a largely academic discussion. We cannot know now how many discs will eventually be mastered using all the capabilities of Atmos - and how many will incorporate limitations and shortcuts. (You may not have noticed, but, until recently, the majority of discs were still 5.1 and not 7.1.)
I would LIKE to hope that, as more people end up owning more capable systems, more discs will be produced that take advantage of all of the capabilities of the system. (And, yes, the Dolby Atmos Demo Disc uses all six height channels; there's even a track that sends a separate test tone to each of the six separate height speakers.)
Of course, the risk is there that most people won't really notice the difference, or care enough to make their preference known to the producers.
from FilmMixer on the AVS Atmos thread - "Here’s where we stand today : We have seen a handful of titles released that are labeled 7.1.4. And it’s been confirmed that is what is indeed on said discs. I haven’t heard of this becoming the new norm for optical discs from most studios." I would debate the "handful" number, more like "multiple handfuls" and growing daily. But what about discs that aren't labelled 7.1.4 but when we play them they are in fact 7.1.4? Does "new norm" refer to only discs labelled 7.1.4 or discs that play back 7.1.4 (even though they aren't labelled 7.1.4)? At the risk of being repetitive, the question I asked weeks ago, does anyone have a disk that actually plays back 9.1.6 (or more)? That's without up mixing, extrapolation or matrixing of course. Cheers Gary |
|
KeithL
Administrator
Posts: 10,273
|
Post by KeithL on Jun 7, 2018 12:03:29 GMT -5
The distances from the speakers to the listening position should be taken care of by the speaker distance settings themselves (which are sort of "outside" of Atmos on home systems). The actual Dolby Atmos Demo Discs do include test tracks that test both 9.1.4 and 9.1.6 (we're talking a blast of white noise that comes sequentially from each speaker). Therefore, you can use that as a test to confirm that a given processor is capable of handling the situation when asked to do so.
You're absolutely correct that limiting the number of objects used will reduce the processing requirements... which will probably mean that low-powered processors will handle those discs better. I'm not sure what that means in real life.... whether they'll screw up less often or handle some aspects of the processing more accurately.
(There may turn out to be "fancy, hard to play discs, that sound real good - but only if you have a powerful processor".)
I do know that the processors we're using in the RMC-1 are much more powerful than those most other folks are using... So, if there is some benefit to be had, we'll have it. (And I'm told that our decoder does sound audibly better than the ones in certain popular, and not especially low cost, processors - who will remain nameless  )
In its full "conceptual" description, an Atmos decoder should be able to work with an arbitrary number of speakers located at fully arbitrary positions. (This is the way it was described in the beginning.) However, from a practical point of view, this is problematic.
First off, it requires a lot more processing power and programming complexity to deal with arbitrary locations than with a set of fixed options... even if you offer lots of options.
Second, it requires a level of validation and limitation.... you simply cannot have a system that works with fully arbitrary positions. If you can figure out the math that will allow you to produce enveloping surround sound using ten speakers, ALL ON THE LEFT SIDE OF THE ROOM, you will be rich. In the mean time, any attempt at allowing "arbitrary speaker positions" is going to require some sort of validation ("you can put the speakers wherever you want - then we'll tell you if your choice will work or not").
Third, because people are familiar with the customary locations, it's simpler to describe things in terms which people are familiar with. (And, as part of that, since Atmos does include bed channels, which are supposed to have fixed locations anyway, you can only offer fully arbitrary positions for extra channels - beyond those - anyway.
The theater system may allow a lot of arbitrary object speakers, but it still expects each of the bed areas to be "populated" with one or more speaker. )
Arguably, Atmos COULD be made to work with fully arbitrary speaker locations, but the results with some choices would be awful... so it does make sense to limit them.
Yes with "bed channels" are still fixed and should be in the same placement as a standard 7.1 system. I was speaking more to the over head channels as there can be some variance in their placement. Of course nothing extreme as all of them on one side of the room, but more to the fact that if the LF speaker is not exactly 2.5' in front and 1.5' to the left of the primary seating position then the sound is distorted. The Atmos system should in theory be able to adjust the sound based on actual speaker placement. Now I do agree that processor power comes into play and maybe that is why we are seeing 7.1.4 labels. If the soundtrack is just broken in channels then the AVR does not have to do as much work, all it has to do is give a preset sound to each preset speaker. In theory a less powerful (cheaper) processor would be needed thus lower priced AVR's could support Atmos. Now if I could just get to test the RMC-1 I will install two extra in ceiling speakers and personally test if sound is coming from either 4 or 6 speakers, I would be doing this for the good of the board, since I am a stand up kinda guy. I am wondering though if 7.1 is used as the base layer for Atmos then a true 9.1.6 setup may never happen. The .6 could all play since they are objects, but most likely only 7 of the 9 speakers would get used since they are base layers. If any sound were to come out of the other 2 "main" speakers I would assume it would be very minor. |
|
|
|
Post by rbk123 on Jun 7, 2018 12:23:45 GMT -5
His point is the processor can mux up sound, ala Dolby IIx or the various spoof formats, and send it to the speakers. No one wants that, rather they want sound specifically intended/encoded for that speaker. If you hear sound from the speaker, there's no way to tell - by listening - if it's the former or the latter. Matrixing or discrete decoding is a known characteristic of a given A/V unit. For a discrete > 16 channel Atmos A/V unit, even if one can look through the Atmos file to identify if it contains positional metadata or not, the only way to acertain that a given speaker is participating in an immersive objective sound is to listen for it or hook a meter or scope up to it. Yes and no. Here the attempt is to determine the encoding. i.e. if it were a DD5.1 disk but you have a 7.1 setup, the processor will mux up the additional 2 speakers. No one disputes that a true DD7.1 encoded disk will sound superior to a DD5.1 encoded disk with the additional 2 surrounds upmixed. |
|
|
|
Post by mgbpuff on Jun 7, 2018 13:31:50 GMT -5
So in a live performance with an orchestra that includes 5 trumpets, how would you objectively determine if one trumpeter was faking it? one of the worst analogies I have read in some time. you are talking about real life individuals...vs what is ENCODED on a disc. if a speaker is not playing any sound (because you stuck you big hairy ear up to it) does NOT mean the disc was not authored to use that speaker...it just means at that given time nothing is being played out of it.....I have a PLETHORA of 7.1 DD discs that have little to just about nothing coming out of the rear speakers (or even the LFE channel)....should I be skeptical of those mixes as well...because...welp...its what my ears tell me.... NO!!! i go by what my processor is reading out. but to go back to your anaology....if each musician is Micd up....I can go to the control board to see OBJECTIVELY if a sound is coming from his mic or not...if i dont do that its just a guessing game Whatif he only lets out a toot once every several stanzas? How long are you going to keep your hairy eyeball on the mixing console? |
|
|
|
Post by musicfan on Jun 7, 2018 13:42:47 GMT -5
|
|
|
|
Post by mgbpuff on Jun 7, 2018 13:44:15 GMT -5
Matrixing or discrete decoding is a known characteristic of a given A/V unit. For a discrete > 16 channel Atmos A/V unit, even if one can look through the Atmos file to identify if it contains positional metadata or not, the only way to acertain that a given speaker is participating in an immersive objective sound is to listen for it or hook a meter or scope up to it. Yes and no. Here the attempt is to determine the encoding. i.e. if it were a DD5.1 disk but you have a 7.1 setup, the processor will mux up the additional 2 speakers. No one disputes that a true DD7.1 encoded disk will sound superior to a DD5.1 encoded disk with the additional 2 surrounds upmixed. Of course, but we know that if a 5.1 file is upmixed to a 7.1 file that it is the artificial work of the processor. So? |
|
|
|
Post by thrillcat on Jun 7, 2018 14:07:53 GMT -5
I don't have Atmos (don't really care that much, but I'm a techie so I like knowing things)....
In theory, with a processor like the Storm, or the Trinnov, or the specific Denons that do 9.1.6 or more, shouldn't a standard Atmos disc send content to all ceiling speakers without any upmixer turned on?
So if you turned off any up mixer and played a disc labeled 7.1.4, that should tell you if it's actually been hamstrung or not, correct?
Or can the Dolby Upmixer not be turned off? The way I have understood things, the Upmixer is for using the ceiling channels on a non-atmos track, like using ProLogic IIx/z is for using height/back channels with 5.1 channel material. If the material is Atmos, it should not require the Dolby Upmixer, right?
It just seems like turning the Upmixer off/on should tell us very simply if those discs have been purposely hamstrung.
|
|
|
|
Post by musicfan on Jun 7, 2018 14:09:09 GMT -5
you cant have the upmixer on when atmos is played....its a disabled feature
like you couldnt use Prologic when DD was being decoded
|
|
KeithL
Administrator
Posts: 10,273
|
Post by KeithL on Jun 7, 2018 14:11:27 GMT -5
First, the short answer to your question is Yes; the RMC-1 will do it. The RMC-1 will ensure that any and all audio information it receives is sent where it should go - based on the number of actual speakers you have.
However, just to be fair, most of this is spelled out in the standard, so ANY product that carries the Dolby and Dolby Atmos logos has to do it. In other words, if we say our processor "supports Dolby Atmos", there are a whole long list of requirements about what we must do, and what we may NOT do. We basically use Dolby approved code in the decoder, and they test each product to make sure it does what it's supposed to. There are some choices; some parts are optional, and some are discretionary, and we can do some extra stuff... but those options are all limited. (And, yes, a more powerful processor may do the job more precisely, or more carefully, but the basic process will be the same.)
However, the way in which Atmos encoded objects are handled on discs is even more tightly "regulated". All Atmos discs are required to be "backward compatible with Dolby TrueHD". That means that you can play ANY Atmos disc on any device that supports TrueHD and it will play correctly (within the limits of your system). Furthermore, by definition, if you play an Atmos disc on a system that only supports TrueHD, YOU WILL NOT LOSE ANY CONTENT.
The Atmos objects are NOT "extra content tracks which a poor processor might fail to add properly into the other channels". The audio information contained in those objects is actually already combined into the TrueHD mix. What the Atmos metadata actually contains is the information necessary to "pull certain things out of the overall mix and handle them as objects". The TrueHD audio stream, which is what you get without the Atmos processing, is already complete.
KeithL , will the RMC-1 be able to do all the Atmos Coolness that you describe with a 5.1 Speaker setup? That is, do it's best to "render" the (X, Y, Z) objects into the 5.1 Speakers? And I guess the same question goes for 7.1 Soundtracks: will the RMC-1 map the Left/Right Rear Speakers of a Lossless Dolby 7.1 Soundtrack to the Left/Right Surround Speakers? Casey |
|
|
|
Post by thrillcat on Jun 7, 2018 14:13:27 GMT -5
you cant have the upmixer on when atmos is played....its a disabled feature like you couldnt use Prologic when DD was being decoded Okay, so if we have reports that the Storm and the Trinnov running a 9.1.6 system and during Atmos playback they are not playing content past 7.1.4 on the specific Disney discs in question that are labeled 7.1.4 Atmos, how is there still a question as to whether or not those discs have been hobbled? I understand that sometimes there might just not be content you're going to hear when you stick your ear up to it, but I find it hard to believe that any disc, in a loud action sequence, would send content to all 7 bed channels, and only 4 of 6 ceiling speakers. That would just be stupid.  |
|
|
|
Post by socketman on Jun 7, 2018 14:46:51 GMT -5
In its full "conceptual" description, an Atmos decoder should be able to work with an arbitrary number of speakers located at fully arbitrary positions. (This is the way it was described in the beginning.) However, from a practical point of view, this is problematic.
First off, it requires a lot more processing power and programming complexity to deal with arbitrary locations than with a set of fixed options... even if you offer lots of options.
Second, it requires a level of validation and limitation.... you simply cannot have a system that works with fully arbitrary positions. If you can figure out the math that will allow you to produce enveloping surround sound using ten speakers, ALL ON THE LEFT SIDE OF THE ROOM, you will be rich. In the mean time, any attempt at allowing "arbitrary speaker positions" is going to require some sort of validation ("you can put the speakers wherever you want - then we'll tell you if your choice will work or not").
Third, because people are familiar with the customary locations, it's simpler to describe things in terms which people are familiar with. (And, as part of that, since Atmos does include bed channels, which are supposed to have fixed locations anyway, you can only offer fully arbitrary positions for extra channels - beyond those - anyway.
The theater system may allow a lot of arbitrary object speakers, but it still expects each of the bed areas to be "populated" with one or more speaker. )
Arguably, Atmos COULD be made to work with fully arbitrary speaker locations, but the results with some choices would be awful... so it does make sense to limit them.
Strangely , dolby still has very definite speaker postitions and the direction they should face. I am talking real atmos not some sound bar/bouncy shite . The Trinnov has that kind of power, i have read where people (rich) that have the auro speaker setup and can map and correct it to work with ATMOS. |
|
|
|
Post by socketman on Jun 7, 2018 14:49:57 GMT -5
First, the short answer to your question is Yes; the RMC-1 will do it. The RMC-1 will ensure that any and all audio information it receives is sent where it should go - based on the number of actual speakers you have.
However, just to be fair, most of this is spelled out in the standard, so ANY product that carries the Dolby and Dolby Atmos logos has to do it. In other words, if we say our processor "supports Dolby Atmos", there are a whole long list of requirements about what we must do, and what we may NOT do. We basically use Dolby approved code in the decoder, and they test each product to make sure it does what it's supposed to. There are some choices; some parts are optional, and some are discretionary, and we can do some extra stuff... but those options are all limited. (And, yes, a more powerful processor may do the job more precisely, or more carefully, but the basic process will be the same.)
However, the way in which Atmos encoded objects are handled on discs is even more tightly "regulated". All Atmos discs are required to be "backward compatible with Dolby TrueHD". That means that you can play ANY Atmos disc on any device that supports TrueHD and it will play correctly (within the limits of your system). Furthermore, by definition, if you play an Atmos disc on a system that only supports TrueHD, YOU WILL NOT LOSE ANY CONTENT. The Atmos objects are NOT "extra content tracks which a poor processor might fail to add properly into the other channels". The audio information contained in those objects is actually already combined into the TrueHD mix. What the Atmos metadata actually contains is the information necessary to "pull certain things out of the overall mix and handle them as objects". The TrueHD audio stream, which is what you get without the Atmos processing, is already complete.
KeithL , will the RMC-1 be able to do all the Atmos Coolness that you describe with a 5.1 Speaker setup? That is, do it's best to "render" the (X, Y, Z) objects into the 5.1 Speakers? And I guess the same question goes for 7.1 Soundtracks: will the RMC-1 map the Left/Right Rear Speakers of a Lossless Dolby 7.1 Soundtrack to the Left/Right Surround Speakers? Casey Which leads us right back to the fact that the production company that isnt giving us the require meta data to reach said 9.1.6 Maybe there are some weak AZZ processor out their that are tripping on too much meta data and they are hiding a conspiracy to protect those people who bought them. |
|
KeithL
Administrator
Posts: 10,273
|
Post by KeithL on Jun 7, 2018 15:15:25 GMT -5
Don't use the term "matrix"... it tends to confuse things since it can mean different things in different contexts.
However, you are quite correct, at least mostly. The Atmos system of encoding does include channels which are mapped to specific speakers or zones - those are the "bed channels".
It also includes "objects", which are indeed mapped to specific X,Y,Z coordinates.
In a normal 7.1.2 or 7.1.4 home theater system... The main speakers (fronts, surrounds, back surrounds) are assigned to the bed channels (so something in the front left bed channel will play from your front left speaker alone). In addition to that, ALL of your speakers may be used to render objects... which will each be played out of the speaker or speakers that will enable it to be placed at the correct X,Y,Z location. And you may have additional speakers, which will be used to to enable more accurate positioning of objects, but which aren't part of the beds.
And, while objects can be placed anywhere, and can be moved around, there's nothing preventing the mix engineer from making objects that happen to line up with specific speakers, and then never moving them, if he wants to do so.
Also bear in mind that this distinction is not as obvious as it may seem at first... An object may be rendered to appear between two speakers by Atmos (in which case it will be playing out of both speakers, creating a "phantom center image" at a point between them.
However, a sound that is recorded on the bed channels could be located in exactly the same spot (you would simply pan it to be between the two speakers). (It can get complicated if you have more than 7.1 "ground level" speakers...... but let's not go there.)
A lot of the confusion arises because of the differences between the theoretical capabilities of Atmos and the practical capabilities of actual home Atmos systems.
Just to be clear, however, the way in which Atmos itself is decoded is spelled out in the standard.
Dolby PLIIx actually serves two purposes.... 1) It can be used as a matrix decoder - which means that it can decode signals specifically encoded for it.
- matrix encoded signals are produced by mixing the channels together in a special way; the decoder uses a similar special process to get the original channels back - the process is imprecise; what you get back from the decoder is more or less similar to what you fed into the encoder, but not exactly the same
(this is a specific characteristic of "most current matrix surround sound encoding/decoding systems", including Dolby PLIIx; it is not a characteristic of many OTHER matrix systems) 2) It can be used as a surround sound SYNTHESIZER to create surround sound channels from existing channels that were never encoded
- it can do this because some of the phase cues it uses to decode encoded signals are randomly present in content that has not been encoded to begin with (as a result, it can do a fair job of "making surround sound out of stereo" or "adding a few extra channels to surround sound content with less channels"
So, you might use Dolby PLIIx.... - to actually play a disc encoded with PLIIx - to "synthesize" surround sound from a stereo signal - one special use is to synthesize a center channel from a stereo signal - to synthesize additional surround channels (many processors use PLIIx to create rear surround channels for use with 7.1 channel systems if the source is only 5.1)
However, much of what you're allowed to do is spelled out in the standard (which means that every licensed product is required to handle most of this the same way.). For example, if you have a 5.1 channel system, and a stereo source, you're welcome to use PLIIx to synthesize surround sound from that stereo signal. However, if you have a Dolby Digital 5.1 input signal, you must decode it using a Dolby Digital decoder.
You are not ALLOWED to decide that you would prefer to decode it into stereo using Dolby Digital, then use PLIIx to synthesize 5.1 channels from it. You may not offer that option on your product (at least not if you want Dolby to license it for sale).
This means that you cannot "make your own processor that decodes Atmos discs using your own methods" (you would be violating any number of licensing and copyright limitations).
His point is the processor can mux up sound, ala Dolby IIx or the various spoof formats, and send it to the speakers. No one wants that, rather they want sound specifically intended/encoded for that speaker. If you hear sound from the speaker, there's no way to tell - by listening - if it's the former or the latter. In a way isn't Atmos sorta of a matrix by design? The object audio is never designed to go to any specific speaker (ie this helicopter sound is on the top right in ceiling speaker) but the sound is coming from X,Y,Z coordinate. It is then up to your AVR to know where your speakers are actually placed in your specific setup (based on doing the calibration etc) and place the sound in the correct speakers that match the XYZ's given by the metadata. Therefore Atmos object audio is never designed to send sound to a specific speaker, just to a specific part of your room and your AVR through the processing should decide what speaker (or speakers) to place that audio from. |
|
|
|
Post by rbk123 on Jun 7, 2018 15:36:49 GMT -5
Of course, but we know that if a 5.1 file is upmixed to a 7.1 file that it is the artificial work of the processor. So? Not sure I follow. The whole point here is figuring out if, using the DD example, they are encoding for 7.1 (or more) or are they only encoding for 5.1? If they are max'ing at 7.1.4, the people with 9.1.6 are going to get lower quality than if it were encoded for 9.1.6. However, those people are going to be a very very small number so I really doubt the studios will care. |
|
|
|
Post by rbk123 on Jun 7, 2018 15:47:07 GMT -5
Of course, but we know that if a 5.1 file is upmixed to a 7.1 file that it is the artificial work of the processor. So? Not sure I follow. The whole point here is figuring out if, using the DD example, they are encoding for 7.1 (or more) or are they only encoding for 5.1? If they are max'ing at 7.1.4, the people with 9.1.6 are going to get lower quality than if it were encoded for 9.1.6. However, those people are going to be a very very small number so I really doubt the studios will care. |
|
|
|
Post by mgbpuff on Jun 7, 2018 15:57:08 GMT -5
Do you stutter too?
|
|
|
|
Post by davidl81 on Jun 7, 2018 16:01:14 GMT -5
Of course, but we know that if a 5.1 file is upmixed to a 7.1 file that it is the artificial work of the processor. So? Not sure I follow. The whole point here is figuring out if, using the DD example, they are encoding for 7.1 (or more) or are they only encoding for 5.1? If they are max'ing at 7.1.4, the people with 9.1.6 are going to get lower quality than if it were encoded for 9.1.6. However, those people are going to be a very very small number so I really doubt the studios will care. I think that in a true Atmos playback nothing should be encoded for 7.1.4. Atmos should be encoded for a 7.1 bed and then objects for the rest of your layout. It should spread out your objects to all of your 9.1.6 speakers (or what ever actual speaker layout you have) if it is a true Atmos encoding. If it is a 7.1.4 encoding (meaning no more XYZ data, just discrete 7.1.4 channels) , then it really isn't Atmos since the .4 channels should be objects not dedicated channels. It would not surprise me if somehow along the way Atmos has just turned into a 7.1.4 format (similar to DD 5.1, 7.1 etc) so it is easier to engineer and process in the HT enviorment. |
|
)
