cc999
Minor Hero
Posts: 38
|
Post by cc999 on Feb 13, 2014 10:40:42 GMT -5
With Dolby PL II it will take a 2 channel 96/192 stereo feed and convert to a 5.1 surround sound signal
at the same bit rate.
Simple YES or NO. Does the UMC support this?
Chas
|
|
KeithL
Administrator 
Posts: 9,938
|
Post by KeithL on Feb 13, 2014 11:41:31 GMT -5
I asked engineering about this....  The math used to decode the various Dolby surround-sound formats is spelled out in the standard itself (and anyone who is licensed by Dolby is required to follow the standard). The PLIIx standard does NOT include processing coefficients for processing audio at 24/192, so no licensed Dolby PLIIx decoder can do so - and this includes the UMC-200. So, in order to apply PLIIx to a 24/192 digital input, any licensed PLIIx decoder MUST downsample it first (and the UMC-200 does so). Of course, since the UMC-200 puts out ANALOG audio anyway, and doesn't output "decoded digital audio" at any bit rate, the question is also sort of moot. All that matters is the sound quality of the analog audio output. (Since PLIIx is a "synthesized" format, and so is about as far from "purist" as you can get anyway, it's also sort of moot on a philosophical level. The only legitimate question is "how good does it sound".) So, the "direct answer" is "No... and neither does anybody else - because the standard doesn't permit it". |
|
cc999
Minor Hero
Posts: 38
|
Post by cc999 on Feb 13, 2014 12:20:07 GMT -5
|
|
|
|
Post by Topend on Feb 13, 2014 13:51:28 GMT -5
You asked if PLllx in the UMC-200 will maintain the high bitrate when converting to surround 5.1. You didn't ask if the UMC-200 has the PLllx codec. Two different questions that require two different answers. Keith answered your original question correctly. On your second question, the answer is yes. Dave. |
|
|
|
Post by Topend on Feb 13, 2014 13:54:02 GMT -5
With Dolby PL II it will take a 2 channel 96/192 stereo feed and convert to a 5.1 surround sound signal at the same bit rate. Simple YES or NO. Does the UMC support this? Chas Just to be clear, the answer is no. Dave. |
|
cc999
Minor Hero
Posts: 38
|
Post by cc999 on Feb 13, 2014 15:17:54 GMT -5
|
|
|
|
Post by urwi on Feb 13, 2014 15:43:48 GMT -5
|
|
|
|
Post by doc1963 on Feb 13, 2014 16:18:56 GMT -5
They are (in name only) and you are not wrong... kinda. ProLogic II is an old codec which was limited to four channels (L/C/R and mono surround) and is no longer used. ProLogic IIx was its replacement (which supports up to 7.1) and has been used in processors and AVRs since 2002. ProLogic IIz (which the UMC-200 has) expands upon PL IIx by adding support for "height" channels. PL IIz has been around since 2009 and is the current PL standard. Hope this helps.....  |
|
cc999
Minor Hero
Posts: 38
|
Post by cc999 on Feb 13, 2014 16:24:13 GMT -5
Better explanation, ty
CC
|
|
|
|
Post by srrndhound on Feb 13, 2014 18:33:19 GMT -5
I asked engineering about this.... The math used to decode the various Dolby surround-sound formats is spelled out in the standard itself (and anyone who is licensed by Dolby is required to follow the standard). Umm, yes it does. It's a simple table to set the time constants. No matter how many times you say it, it's still incorrect. |
|
|
|
Post by Topend on Feb 13, 2014 21:02:24 GMT -5
I asked engineering about this.... The math used to decode the various Dolby surround-sound formats is spelled out in the standard itself (and anyone who is licensed by Dolby is required to follow the standard). Umm, yes it does. It's a simple table to set the time constants. No matter how many times you say it, it's still incorrect. Hi Srrndhound, Do you have any evidence to support your claim? Thanks, Dave. |
|
|
|
Post by srrndhound on Feb 13, 2014 22:56:00 GMT -5
Do you have any evidence to support your claim? Hi Dave. I invented PLIIx. Is that sufficient? The confusion might be that certain DSPs do not support 192 kHz PLIIx. I am referring only to the PLIIx code as prepared by Dolby. |
|
|
|
Post by Topend on Feb 13, 2014 23:39:10 GMT -5
Do you have any evidence to support your claim? Hi Dave. I invented PLIIx. Is that sufficient? That is not the answer I was expecting. As you may understand as this is the internet I have to take something written on a forum in good faith. Cheers, Dave. |
|
|
|
Post by cwt on Feb 14, 2014 1:35:22 GMT -5
CC ; The problem has stemmed from the way people have read your initial question I feel . I think your asking if the 2 cirrus logic chips in the umc200 are capable of taking a 24/96 or 24/192 2ch pcm signal and not downrezing it before applying pl2 . Havent tried the higher sampling rate but I would say yes as many other avr's etc only have 1 chipset that havent the horsepower and do certainly downrez  This is a quote from the 200 web page ; If someone has a 2l trondheime solistene or a bluray like 'akira' with a 5.1 24/192 soundtrack Ide be confident even these would be no problem Maybe someone with a hd track 2ch download or similar can confirm ? Pl2x is a much more advanced algorithm than pl2 so if you can manage 2 more speakers this maybe an option too ? |
|
|
|
Post by urwi on Feb 14, 2014 5:19:00 GMT -5
I asked engineering about this.... The math used to decode the various Dolby surround-sound formats is spelled out in the standard itself (and anyone who is licensed by Dolby is required to follow the standard). Umm, yes it does. It's a simple table to set the time constants. No matter how many times you say it, it's still incorrect. Now I'm confused. Who is right? Emotiva or srrndhound? I can't believe that Keith and Emotiva engineering don't know how their products operate. |
|
|
|
Post by doc1963 on Feb 14, 2014 10:00:20 GMT -5
Umm, yes it does. It's a simple table to set the time constants. No matter how many times you say it, it's still incorrect. Now I'm confused. Who is right? Emotiva or srrndhound? I can't believe that Keith and Emotiva engineering don't know how their products operate. IMO, both. Keith is speaking from a "hardware" point of view and srrndhound from a "software" point of view. Although the Dolby software may allow it, you'd be hard pressed to find a processor or AVR (outside of an HTPC) that has enough horsepower and on-board memory to process a multichannel sampling frequency above 96kHZ. Anything above would need to be downsampled to a frequency that the DSP (and associated hardware) can handle. Also IMO, should there be a big deal over it...  Dolby TrueHD software can process 7.1 up to 24/96kHz and 5.1 up to 24/192, but how may discs are actually encoded at these bit rates and, if so, how many AVRs can process them without downsampling?.....  |
|
|
|
Post by urwi on Feb 14, 2014 11:09:39 GMT -5
Although the Dolby software may allow it, you'd be hard pressed to find a processor or AVR (outside of an HTPC) that has enough horsepower and on-board memory to process a multichannel sampling frequency above 96kHZ. Anything above would need to be downsampled to a frequency that the DSP (and associated hardware) can handle. I agree but this is different from what KeithL said. The PLIIx standard does NOT include processing coefficients for processing audio at 24/192, so no licensed Dolby PLIIx decoder can do so - and this includes the UMC-200. |
|
KeithL
Administrator
Posts: 9,938
|
Post by KeithL on Feb 14, 2014 12:17:14 GMT -5
Perhaps I've been phrasing this unclearly (and, yes, this is all "as I understand it") .... If all this really concerns you, then please skip to the last paragraph and read it first  (And then go listen to some music - it's Friday...) The Dolby license requirement spells out the "necessary" capabilities required to license a product quite explicitly. This is different than the basic coefficients on which the process is based. In order to be licensed as supporting a specific Dolby decoding mode (like PLIIx), a product must support certain decoding modes, at certain quality levels, and do so using certain equations - and the equations and programming required to do so are spelled out by Dolby. If you want to use the Dolby logo, you do it the way they say. The actual coefficients on which the programming is based are indeed entirely generic, but the requirements of a specific implementation - in order to "meet the standard" and "comply with the license" - are not. According to our engineering department, the "official Dolby code" does NOT include support for high bit rates. So, in terms of "licensed modes", it isn't there. This is not to say that someone couldn't write their own code which implemented the original coefficients; that code would then comply with the original requirements, meet the standard, and also be able to do things not required by the standard itself... (The theory behind a CODEC often differs from the implementation. Some of those nice Greek symbols in the conceptual diagrams don't translate exactly in real life, and so the actual code may involve compromises or tolerance ranges. The licensing specifies those limitations and tolerances - which may be somewhat different than the nice theoretical equations. Its' easy to say "shift one channel by 90 degrees and add it to the other one" but, in reality, it cannot be done without some compromises - performing the required alteration results in other changes to the signal. Dolby controls the quality of the entire process by specifying BOTH.... and then confirming that the end product delivers the correct output within their specified limits.) To be TOTALLY clear, however, the UMC-200 does not output ANY decoded signals in digital form. It processes PLIIx signals in accordance with the requirements of Dolby's standard and license, and gives you the correct analog output for a given input and mode selection - which has been confirmed as part of the licensing process. As it so happens, when processing PLIIx, if a high-bit-rate input (24/192) is received, it WILL be down-sampled before being processed; which is also in accordance with the Dolby spec. HOWEVER, the bit rate of the signal between the processor and the DACs is totally moot; all that really matters is the output that you actually have access to (and listen to), which is the analog output. (And, to be totally honest, if you're concerned enough with the accuracy of your audio signal to worry about whether the bit rate is maintained or not, then you really should know better than to feed that signal through a PLIIx decoder - which synthesizes fake surround sound by applying assorted phase shifts to the audio, then mixing it together in various ways. Since the signal was not originally encoded, these all constitute the PLIIx decoder "guessing what will sound nice" - which is about as far from "accurate audiophile sound" as you can get. PLIIx itself is modifying the signal so drastically that any difference that might be audible due to a difference in bit rate will be trivial by comparison. Obviously, getting a result that sounds good is important, but worrying about "accuracy" or "fidelity to the original" is entirely a lost cause.) The PLIIx standard does NOT include processing coefficients for processing audio at 24/192, so no licensed Dolby PLIIx decoder can do so - and this includes the UMC-200. [/quote] |
|
|
|
Post by srrndhound on Feb 14, 2014 13:57:40 GMT -5
Perhaps I've been phrasing this unclearly Yes. And the short reply would have been "I stand corrected." Instead, you go off the deep(er) end with more misinformation. I though we were talking about PLIIx. PLIIx is not a CODEC. There are no phase shifts involved in PLIIx. Where do you get this stuff?? One can accept the brilliance of surround sound pioneers like Jim Fosgate (PLII) or Dr. Greisinger (Logic7) for what it is, but "guessing what will sound nice" is not being fair to their art. Guessing what will sound nice is what comes out the headphone jack of the UMC-200. It's still broken, is it not? Perhaps I missed the update that addressed it. I think you don't mean bit rate, but sample rate. And yes, no one should waste a minute worrying about 192 kHz. It serves no purpose, and can do more harm than good. |
|
cc999
Minor Hero
Posts: 38
|
Post by cc999 on Feb 14, 2014 16:30:28 GMT -5
Just for the record I put my money on srrndhound's replies.
I see too many times in this forum a simple question put
in terms of confusion. Now confronted by the expert they back track. Interesting.
Chas
|
|
This is a quote from the 200 web page ; 
Dolby TrueHD software can process 7.1 up to 24/96kHz and 5.1 up to 24/192, but how may discs are actually encoded at these bit rates and, if so, how many AVRs can process them without downsampling?..... 
