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Official OPPO BDP-93 Owner's Thread - Page 844

post #25291 of 26645
My personal recommendation is to use LPCM. Among other things, that means you can leave Secondary Audio set to ON all the time without risking loss of quality.

But there are exceptions. For example, I watch a lot of classic movies on Blu-ray, and sometimes these Mono tracks are on disc as 1.0 -- e.g., DTS-HD MA 1.0 48KHz. Now, if you play that as Bitstream, your AVR will see it as 1.0, so you will get Center and Subwoofer (due to bass management in the AVR).

But if you play it as LPCM the minimum configuration over HDMI is 2.0 -- what's called Dual Channel Mono. A decent AVR will provide a way to collapse that to 1.1 (Center plus Sub), but if you don't think to do that, or if your AVR doesn't support that, then you'll get 2.0 -- Mono presented equally in the LF and RF speakers, which isn't quite the same.

As a Beta Tester I regularly cycle through all of the audio output possibilities, basically trying to scare up new bugs. And so I've learned to appreciate that there's never JUST ONE "best" way to do it for every track. So experiment and find out your own favorite ways to do things.

However, if you are looking for a simple answer to get started, as I said above, my recommendation is HDMI Audio LPCM, Secondary Audio ON, Dynamic Range Control OFF, DTS Neo:6 Mode OFF, SACD Output PCM, and HDCD Decoding ON (unless your AVR does it for HDMI Input in which case you need to leave it OFF in the OPPO).

As for your specific question, I've not heard of a case where an Audyssey implementation could work with Bitstream input but could not work with LPCM input. Such a case may exist, but it would be rather surprising as Audyssey uses LPCM in its processing, so sending it a Bitstream means the EXTRA work of decoding the Bitstream into LPCM also has to happen.
--Bob
post #25292 of 26645
Quote:
Originally Posted by Bob Pariseau View Post

My personal recommendation is to use LPCM. Among other things, that means you can leave Secondary Audio set to ON all the time without risking loss of quality.

But there are exceptions. For example, I watch a lot of classic movies on Blu-ray, and sometimes these Mono tracks are on disc as 1.0 -- e.g., DTS-HD MA 1.0 48KHz. Now, if you play that as Bitstream, your AVR will see it as 1.0, so you will get Center and Subwoofer (due to bass management in the AVR).

But if you play it as LPCM the minimum configuration over HDMI is 2.0 -- what's called Dual Channel Mono. A decent AVR will provide a way to collapse that to 1.1 (Center plus Sub), but if you don't think to do that, or if your AVR doesn't support that, then you'll get 2.0 -- Mono presented equally in the LF and RF speakers, which isn't quite the same.

As a Beta Tester I regularly cycle through all of the audio output possibilities, basically trying to scare up new bugs. And so I've learned to appreciate that there's never JUST ONE "best" way to do it for every track. So experiment and find out your own favorite ways to do things.

However, if you are looking for a simple answer to get started, as I said above, my recommendation is HDMI Audio LPCM, Secondary Audio ON, Dynamic Range Control OFF, DTS Neo:6 Mode OFF, SACD Output PCM, and HDCD Decoding ON (unless your AVR does it for HDMI Input in which case you need to leave it OFF in the OPPO).

As for your specific question, I've not heard of a case where an Audyssey implementation could work with Bitstream input but could not work with LPCM input. Such a case may exist, but it would be rather surprising as Audyssey uses LPCM in its processing, so sending it a Bitstream means the EXTRA work of decoding the Bitstream into LPCM also has to happen.
--Bob



Thanks for the info, this leaves me wondering what my Marantz AV8801 does with HDCD decoding. I use Audyssey all the time so if it uses LPCM it only makes sense to send it LPCM. I know most of the guys on the 8801 thread bitstream through HDMI, but that doesn't make them correct.
post #25293 of 26645
It was prettying told to me the same way as bob explained it. I can't argue with the results.
Edited by pwrjnky - 6/27/13 at 3:07pm
post #25294 of 26645
Add to what Bob just said the authoring glitches (probably due to efforts to combat piracy) that cause audio dropouts when bitstreaming that can be avoided by sending LPCM.

As a confirmed analog-out guy (I've never had an amp made since HDMI was introduced), I can testify to the quality of the Oppo's audio handling - it's become the centerpiece of my high-def audio network, playing stereo flacs at up to 192/24 and surround flacs at up to 96/24.

-Phil
post #25295 of 26645
Quote:
Originally Posted by Philnick View Post

Add to what Bob just said the authoring glitches (probably due to efforts to combat piracy) that cause audio dropouts when bitstreaming that can be avoided by sending LPCM.

As a confirmed analog-out guy (I've never had an amp made since HDMI was introduced), I can testify to the quality of the Oppo's audio handling - it's become the centerpiece of my high-def audio network, playing stereo flacs at up to 192/24 and surround flacs at up to 96/24.

-Phil



Hi, one thing I did find out when using Audyssey those high res files get reduced to 48/24, which kind of ticked me off. That said if no one told me I would have never known. I do believe there are a couple of pre/pros and or AVR's that leave the high res files as is with room correction engaged. Whether this is Audyssey or another room correction I'm not sure.
post #25296 of 26645
Just looked in the manual (old PDF) but didn't find an answer to the following question:
Watching a Disney BR disc last night, I noticed the sound was monaural. After pressing the info button & saw, in the bottom left corner where the disc icons are a "1" (forgot the rest of the display).
After stopping disc & entering setup, I changed to 7.1 DTS & resumed. Now the display (on screen) showed a 3/7 ? I never understood what these numbers referred to. Can anyone explain what the icons reflect & the numbers associated? I'm not referring to the alpha description such as DTS 5.1 but the circles with the number. Not at my unit right now so forgive me for the vague visual but I am relying on memory.
BTW, the disc was the new prequel "OZ".
post #25297 of 26645
If I'm understanding: the circles logo on the lower left indicate normal audio processing. If it were jagged waveform that would mean Secondary Audio processing.

-Bill
post #25298 of 26645
Of you missed it in the beginning. The new wizard of oz movie comes set for only 2 channel stereo for some reason. You need to go into set up and into language and switch it into surround. Never seen that before, but I'm sure that's your problem.

Never mind. Just re read your post and saw that you changed it.
Edited by pwrjnky - 6/27/13 at 7:11pm
post #25299 of 26645
I have an Oppo 95 but it can not read all HDD on dock Orico 4bay. Pls advise with thanks
post #25300 of 26645
This may be a little off topic, but it is related to the Oppo 93. I'm sure I'm doing something very stupid, but I can't figure out what. In my old environment I had windows Vista on my PC and the Oppo 93. I played a little with DLNA and it worked fine. I used a few different DLNA servers, and they all worked. This included connecting to the Oppo as well as a PS3. I have now upgraded to a new PC with Windows 8, 64 bit. I have been trying to get DLNA back up and running. I am using Windows Media Server and Twonkey. The Oppo, the PS3 and the Panasonic TV can all see and function on the internet. However, none of them see either media server. I have played with the HomeGroup function and I believe that I am sharing pictures and music. I have tested by turning off the firewall on the PC and the router. Nothing I have tried allows any of the devices to see the media servers. I am obviously missing something. Any help or direction would be appreciated. Thanks.
post #25301 of 26645
Quote:
Originally Posted by htwaits View Post

My understanding is that the first step any AVR takes with a bitstream digital signal it to convert it to LPCM which is also digital. My Denon receivers very definitely perform EQ processing on LPCM digital input. In my limited AVR experience, and from reading OPPO threads, my understanding is that if the input is analog, the signal has to be converted back to digital for processing to take place. If there is a restriction on LPCM digital input, I've missed it. eek.gifsmile.gif

I have a 7.1 system and leave ProLogic IIx on by default to upmix everything to 7.1. My Denon receiver is a few years old. I'm pretty sure (though I haven't tried it in a while) that it will not apply ProLogic IIx to multi-channel PCM input signals, only to bitstream or to 2-channel PCM. If I feed it a PCM 5.1 signal, only those specific 5.1 channels will be active. This is an issue primarily on older Blu-rays (like House of Flying Daggers) that are encoded with PCM 5.1 soundtracks.

Maybe I need to test this again, but that's what I believe happens.
post #25302 of 26645
Quote:
Originally Posted by htwaits View Post

My understanding is that the first step any AVR takes with a bitstream digital signal it to convert it to LPCM which is also digital.
Yes. An encoded bitstream is like a zip file. It must be decoded back into PCM before a receiver can do any processing such as bass management, room correction, channel expansion, and the digital-analog conversion.
Quote:
My Denon receivers very definitely perform EQ processing on LPCM digital input.
That's the case with most processors these days. In the past, some functionality was limited on some receivers based on the type of input - usually when dealing with lossless dts-MA bitstreams, but sometimes affecting multichannel PCM inputs
Quote:
In my limited AVR experience, and from reading OPPO threads, my understanding is that if the input is analog, the signal has to be converted back to digital for processing to take place. If there is a restriction on LPCM digital input, I've missed it. eek.gifsmile.gif
Yes, analog sources must be converted to digital before any digital signal processing can be applied. As noted earlier, limitations with bitstream and PCM inputs may happen based on specific engineering issues with some receivers.
post #25303 of 26645
Based on input from Bob P and others, I've decided for the time being to have my Oppo output LPCM rather than DSD or Bitstream. Not sure if I hear a difference yet, but I'm assuming that my Oppo can do a better job at decoding than my Anthem MRX-500. Listening to a great jazz disc by Tsuyoshi Yamamoto (Misty) right now and it sounds wonderful with Oppo doing the heavy lifting.
post #25304 of 26645
Decoding will be identical regardless of whether it is done in the player or the receiver. With digital transmission, all subsequent processing happens in the receiver. So, it really doesn't matter where the decoding is done. You get the same PCM either way.
post #25305 of 26645
Quote:
Originally Posted by comfynumb View Post

Hi, one thing I did find out when using Audyssey those high res files get reduced to 48/24, which kind of ticked me off. That said if no one told me I would have never known. I do believe there are a couple of pre/pros and or AVR's that leave the high res files as is with room correction engaged. Whether this is Audyssey or another room correction I'm not sure.

Well, I never had any confidence in such systems in the first place: why let something as touchy as microphone placement - given the varying locations of nodes at different frequencies - be used to apply equalization to a system? I prefer to use my ears, the channel gains, and the channel distance settings, to make the speakers sound balanced - and other than trimming the sub-woofer level by ear, I leave all other tone controls at flat.

48/24 is what the movie industry considers "top-shelf" audio. While Blu-ray disks can carry lossless surround at up to 192/24, even 96/24 is rare. Of the approximately 120 Blu-ray movies and concerts I have (about 25% of them being concerts), only about a quarter (mostly dramatic films) are even 48/24, and only one (Eric Clapton's 2010 Crossroads Guitar Festival) is 96/24.

The greater dynamic range of 24 bit samples allows both for subtler, more transparent sound and for louder dramatic peaks. I've been decoding my handful of HDCD CDs - most of them by Joni Mitchell, all of whose CDs are HDCD-encoded, allowing for 20-bit sound instead of CD's usual 16-bit depth. Feed the Oppo an HDCD disk and it will recognize it as an HDCD and decode it, but over a network it won't see it as being an HDCD. I did some web searching and found a tiny command line freeware program called HDCD.exe, which will read an HDCD-encoded WAV file and write out a decoded WAV in 24 bit format, though the last 4 bits are just padded out with zeros. I do this one track at a time with the following command:

HDCD < filename (with the spaces removed - quote marks won't help).WAV > filename-24.wav

I then have Winamp turn the 24 bit WAVs into FLACs that I can tag in the usual manner using MP3tag. (I drag the files to Winamp's Play List window, highlight them all with Ctrl-A, do a right-click and choose Send to -> Format Converter.)

The Oppo plays the decoded files over the network with full dynamic range, and they sound great. To allow for greater headroom, the average volume of the converted files is about 6db down from before conversion, which is easy enough to correct for by turning up the volume a little. The increased separation in volume levels between lead and background instruments creates greater openness and transparency in the mix. This is the exact opposite of what has become all to common in mixing music today, where the background is cranked up almost as loud as the lead, making for a nearly-constant volume level, which is tiring to the ears (and brain).

The higher sample rates are valuable also, as they allow for a clearer picture of the actual sound waves. While Nyquist postulated that a sample rate can capture a top frequency up to half the sample rate, that's a limit, not a recommendation - a total of two samples per cycle isn't a very complete picture. Better four samples (96 KHz sampling) or eight (192 KHz sampling). Let the debate rage over whether we can hear frequencies higher than 20 KHz. I believe we can, but even those who don't should be able to agree that a more complete picture of the frequencies they agree we can hear is worth trying for.
Edited by Philnick - 6/28/13 at 12:26pm
post #25306 of 26645
Quote:
Originally Posted by Josh Z View Post

Quote:
Originally Posted by htwaits View Post

My understanding is that the first step any AVR takes with a bitstream digital signal it to convert it to LPCM which is also digital. My Denon receivers very definitely perform EQ processing on LPCM digital input. In my limited AVR experience, and from reading OPPO threads, my understanding is that if the input is analog, the signal has to be converted back to digital for processing to take place. If there is a restriction on LPCM digital input, I've missed it. eek.gifsmile.gif

I have a 7.1 system and leave ProLogic IIx on by default to upmix everything to 7.1. My Denon receiver is a few years old. I'm pretty sure (though I haven't tried it in a while) that it will not apply ProLogic IIx to multi-channel PCM input signals, only to bitstream or to 2-channel PCM. If I feed it a PCM 5.1 signal, only those specific 5.1 channels will be active. This is an issue primarily on older Blu-rays (like House of Flying Daggers) that are encoded with PCM 5.1 soundtracks.

Maybe I need to test this again, but that's what I believe happens.
We have a 5.1 system and the first time that Jeff Meier (UMR at AVS) calibrated the audio our Denon was the 3806 which had no bitstream capability. Also I've never gotten into up mixing audio so that's an area where my ignorance shines through. wink.gif

Bob Pariseau is my self appointed OPPO guru in all these kinds of areas. cool.gif
post #25307 of 26645
Quote:
Originally Posted by BIslander View Post

Decoding will be identical regardless of whether it is done in the player or the receiver. With digital transmission, all subsequent processing happens in the receiver. So, it really doesn't matter where the decoding is done. You get the same PCM either way.

In theory - however, "there's many a chip between the cup and the lip," so some transcoders will have better sound than others if the signal goes through an analog step in between the disk's bitstream and the PCM it's transcoded to.

I happen to think the Oppo has superb audio quality all the way down the chain to the analog outs, and can easily imagine that there may be AVRs that don't do as well - particluarly since some "advanced" blu-ray disks give many AVRs indigestion if fed the disk's bitstream rather than LPCM.

-Phil
post #25308 of 26645
Quote:
Originally Posted by Philnick View Post


Well, I never had any confidence in such systems in the first place: why let something as touchy as microphone placement - given the varying locations of nodes at different frequencies - be used to apply equalization to a system? I prefer to use my ears, the channel gains, and the channel distance settings, to make the speakers sound balanced - and other than trimming the sub-woofer level by ear, I leave all other tone controls at flat.

48/24 is what the movie industry considers "top-shelf" audio. While Blu-ray disks can carry lossless surround at up to 192/24, even 96/24 is rare. Of the approximately 120 Blu-ray movies and concerts I have (about 25% of them being concerts), only about a quarter (mostly dramatic films) are even 48/24, and only one (Eric Clapton's 2010 Crossroads Guitar Festival) is 96/24.

The greater dynamic range of 24 bit samples allows both for subtler, more transparent sound and for louder dramatic peaks. I've been decoding my handful of HDCD CDs - most of them by Joni Mitchell, all of whose CDs are HDCD-encoded, allowing for 20-bit sound instead of CD's usual 16-bit depth. Feed the Oppo an HDCD disk and it will recognize it as an HDCD and decode it, but over a network it won't see it as being an HDCD. I did some web searching and found a tiny command line freeware program called HDCD.exe, which will read an HDCD-encoded WAV file and write out a decoded WAV in 24 bit format, though the last 4 bits are just padded out with zeros. I do this one track at a time with the following command:

HDCD < filename (with the spaces removed - quote marks won't help).WAV > filename-24.wav

I then have Winamp turn the 24 bit WAVs into FLACs that I can tag in the usual manner using MP3tag. (I drag the files to Winamp's Play List window, highlight them all with Ctrl-A, do a right-click and choose Send to -> Format Converter.)

The Oppo plays the decoded files over the network with full dynamic range, and they sound great. To allow for greater headroom, the average volume of the converted files is about 6db down from before conversion, which is easy enough to correct for by turning up the volume a little. The increased separation in volume levels between lead and background instruments creates greater openness and transparency in the mix. This is the exact opposite of what has become all to common in mixing music today, where the background is cranked up almost as loud as the lead, making for a nearly-constant volume level, which is tiring to the ears (and brain).

The higher sample rates are valuable also, as they allow for a clearer picture of the actual sound waves. While Nyquist postulated that a sample rate can capture a top frequency up to half the sample rate, that's a limit, not a recommendation - a total of two samples per cycle isn't a very complete picture. Better four samples (96 KHz sampling) or eight (192 KHz sampling). Let the debate rage over whether we can hear frequencies higher than 20 KHz. I believe we can, but even those who don't should be able to agree that a more complete picture of the frequencies they agree we can hear is worth trying for.



I have the new Marantz AV8801 pre/pro and no one was more skeptical of Audyssey than I was. I have to admit I spent weeks adjusting the sound to my liking. I ended up running Audyssey and XT32 and although it came up with some bewildering settings for my acoustically horrible room, after a few tweaks I loved the sound. The Dyn EQ is amazing especially at low to medium volumes. I'm going to run it again with a dedicated mic stand and boom and that coupled with my new Oppo settings (thanks to Bob P) I expect it to sound great smile.gif I am also going to set it up for 2 channel which I understand the 8801 is very capable of.
Edited by comfynumb - 6/28/13 at 2:16pm
post #25309 of 26645
Quote:
Originally Posted by Philnick View Post

Quote:
Originally Posted by BIslander View Post

Decoding will be identical regardless of whether it is done in the player or the receiver. With digital transmission, all subsequent processing happens in the receiver. So, it really doesn't matter where the decoding is done. You get the same PCM either way.

In theory - however, "there's many a chip between the cup and the lip," so some transcoders will have better sound than others if the signal goes through an analog step in between the disk's bitstream and the PCM it's transcoded to.

I happen to think the Oppo has superb audio quality all the way down the chain to the analog outs, and can easily imagine that there may be AVRs that don't do as well - particluarly since some "advanced" blu-ray disks give many AVRs indigestion if fed the disk's bitstream rather than LPCM.

-Phil
No doubt on analog. But, scirica is not using the Oppo's analog output. He's merely having the Oppo do the decoding instead of his Anthem and there's zero advantage to that. Scirica used the term "heavy lifting" in reference to decoding, which overstates what the Oppo is doing. Decoding simply unzips a file to produce PCM, which is the exact same PCM that his receiver would produce. The player does nothing beyond that. It simply sends the resulting PCM to the receiver for the real heavy lifting - bass management, room correction, and any other digital processing that the user applies. With digital, those tasks are performed by the receiver regardless of where the decoding is done.

I am not aware of the AVR indigestion that you mention with some Blu-ray bitstreams. In fact, while I do not subscribe to the notion that jitter produces audible differences, PCM transmission is subject to jitter while a bitstream is not. So, if anything, a bitstream would likely be better rather than worse. In the end, they will be the same in almost all circumstances.

This is no big deal. But, while Oppo makes great players, this is one area where there's no improvement. In fact, p62 of the owner's manual says this about bitstream:
This option is recommended when connecting the HDMI output to an A/V receiver or processor that supports advanced audio decoding, such as Dolby TrueHD and DTS-HD Master Audio.
The manual says PCM should be used when the receiver lacks lossless decoders.

btw, it's not possible for a track to go through an analog step between bitstream and PCM. And I don't know that transcoding is the right word to use in reference to a digital-analog conversion. An encoded file is like a zipped up data file. PCM gets fed into the encoder, where it is zipped up. It comes back out of the decoder as PCM. The digital-analog conversion happens at the end of the process, not as a step along the way.
Edited by BIslander - 6/28/13 at 2:06pm
post #25310 of 26645
Quote:
Originally Posted by BIslander View Post

No doubt on analog. But, scirica is not using the Oppo's analog output. He's merely having the Oppo do the decoding instead of his Anthem and there's zero advantage to that. Scirica used the term "heavy lifting" in reference to decoding, which overstates what the Oppo is doing. Decoding simply unzips a file to produce PCM, which is the exact same PCM that his receiver would produce. The player does nothing beyond that. It simply sends the resulting PCM to the receiver for the real heavy lifting - bass management, room correction, and any other digital processing that the user applies. With digital, those tasks are performed by the receiver regardless of where the decoding is done.

I am not aware of the AVR indigestion that you mention with some Blu-ray bitstreams. In fact, while I do not subscribe to the notion that jitter produces audible differences, PCM transmission is subject to jitter while a bitstream is not. So, if anything, a bitstream would likely be better rather than worse. In the end, they will be the same in almost all circumstances.

This is no big deal. But, while Oppo makes great players, this is one area where there's no improvement. In fact, p62 of the owner's manual says this about bitstream:
This option is recommended when connecting the HDMI output to an A/V receiver or processor that supports advanced audio decoding, such as Dolby TrueHD and DTS-HD Master Audio.
The manual says PCM should be used when the receiver lacks lossless decoders.

btw, it's not possible for a track to go through an analog step between bitstream and PCM. And I don't know that transcoding is the right word to use in reference to a digital-analog conversion. An encoded file is like a zipped up data file. PCM gets fed into the encoder, where it is zipped up. It comes back out of the decoder as PCM. The digital-analog conversion happens at the end of the process, not as a step along the way.

Actually, at least with DTS HD Master Audio, it's more complex than just "unzipping" a file (a purely digital process that consists of replacing the shorthand tokens that replace common strings with copies of those strings): DTS proclaims that its package contains a lossy 5.1 "core" for processing by older AVRs plus multiple layers of "extensions" to be used by more recent AVRs to be added back to the core to losslessly recreate the original signal. How that is done is beyond my ken, and in fact that of most player and AVR manufacturers for the first few years of Blu-ray's existence. I don't know if that is done entirely in the digital domain or not. If it is done entirely digitally it would indeed be "transcoding," but would be a complex process capable of being done well or poorly, depending on how the procedure is implemented.

As to the other point, audio dropouts on newly released disks caused by new authoring techniques is a topic often-discussed in this thread and, I believe, those of other manufacurers' players, and the workaround that is most commonly suggested is setting the player to send LPCM to the AVR, which sidesteps the problem. That's what I referred to by my "bitstream indigestion" phrase, and I think is part of why Bob recommends using LPCM.
Edited by Philnick - 6/28/13 at 7:57pm
post #25311 of 26645
Phil - I am sure your position seems sensible to you. But, here's the bottom line: if one lossless decoder produces an output different from another lossless decoder when fed the same input source, then one of them is not lossless. But, in the half dozen years that dts-MA and TrueHD have been around, I have never seen a single credible source question whether any decoder certified by Dolby or DTS fails to produce the correct output. How have you come to the conclusion that some decoders are inferior to others and that the Oppo decoder is better?

I don't understand your point about the complexity of the DTS-HD Master Audio structure. It may be complicated. But, there's nothing to indicate that certified decoders get it wrong. btw, TrueHD also uses a core+extension structure, but one built around a lossless 2 channel core where the extensions add the data for 5.1 and 7.1 outputs. The evidence suggests it works just fine, too.

I can assure you the entire encoding/decoding process happens digitally. As I explained, there can't be an analog conversion until after the encoded file is turned back into PCM. What would be converted? It's like saying you can change the fonts on a document that's been zipped up before you unzip it.

The OP on this issue was not dealing with a problem disc. Posts in this thread appear to have led him to the conclusion that his Oppo does a better job of decoding than his receiver. I weighed in to explain why that is not the case. And remember, at the end of the day, Oppo recommends bitstreaming rather than player decoding when the processor has lossless decoders.
post #25312 of 26645
All good information. Since I have rarely experienced blu-ray audio dropouts (and as mentioned above I'm feeding my Anthem via HDMI), I'm leaving my Oppo on bitstream output. I have not noticed any difference in sound quality, nor did I expect to.

Love the discussion here. At least we all agree that Oppo makes a great universal player!
post #25313 of 26645
Barring bugs in either device, correctness (e.g., quality) of the decode is not the issue.

My preference for using LPCM is that it allows me to leave Secondary Audio ON without having to worry about the quality loss that results from RE-encoding the audio back into a (lossy) bitstream for output.

If you look at oddball cases in the formats, for the 93/95 there's actually a preference for using Bitstream. For example, the rare DTS-HD MA 5.1 192KHz format (found on some music discs) can not be decoded as 192KHz in the 93/95. The LPCM output is 96KHz. But the Bitstream output carries the full 192KHz in case the AVR wants to take a stab at decoding that (many AVRs of that vintage ALSO have the limitation to 96KHz for that). In the legacy lossy formats, some matrixed Rear channel info (e.g., DTS-ES) does not get decoded in the 93/95, but gets passed in the Bitstream. These are all remnants of the "DTS Essentials" decoder that DTS was licensing for Blu-ray players back when the 93/95 came out.

That's no longer happening, so the 103/105 don't have such oddball case limitations.

Barring both bugs and the oddball cases, if you are hearing a difference between LPCM and Bitstream, odds are there is a small VOLUME difference between the two decodes (and the subsequent processing path for both). Even a fraction of a dB Volume difference will be sensed as the "louder" one is the "better" one. Another difference can show for folks with a 5.1 speaker configuration attached to a 7.1 capable AVR. DTS imposes different decoding rules for 7.1 tracks if the decoder knows the output is destined for 5.1 speakers. When you send the Bitstream, the AVR doing the 7.1 to 5.1 decode is burdened with those rules. But when you send LPCM, the OPPO sees the AVR as accepting 7.1 input and thus does a "normal" 7.1 decode to LPCM (which the AVR then down-mixes to 5.1 speaker output). SO, it is possible to perceive a quality difference between the 7.1 to 5.1 DECODE and the 7.1 decode in the OPPO followed by the subsequent DOWN-MIX to 5.1 in the AVR. (With EITHER WAY possibly being perceived as "better"!)

There are also cases of lesser quality AVRs which handle HDMI LPCM input poorly. I.e., they don't buffer and re-clock it to make sure the data is properly transferred. With Bitstream input, the AVR isn't faced with having to do that, and so they can get away with cutting that particular corner. If your AVR offers adjustable lip-sync delay which functions when using HDMI LPCM input, then it has to buffer and re-clock. If not, then maybe they cut that corner and Bitstream input will be "better" because LPCM input is not being handled properly.

And as mentioned above, there are also cases of AVRs that don't have enough horsepower to decode all the various Bitstream input formats *AND* provide processor intensive audio processing such as Room Correction.

Confused yet?

The bottom line is, don't accept any glib answers here. Try both ways -- watching out for volume differences, and limitations (gotchas!) imposed by the implementation -- and use whichever one YOU like. If you can't hear a difference, and don't care about leaving Secondary Audio ON in the OPPO, and aren't blocked by processor implementation gotchas, then go ahead and use Bitstream, as it has the important added advantage of allowing your AVR to light up its DTS-HD MA or Dolby TrueHD input format lamp on the front panel. And we all know audio sounds better when those lamps are lit. biggrin.gif
--Bob
Edited by Bob Pariseau - 6/29/13 at 8:59am
post #25314 of 26645
Quote:
Originally Posted by Bob Pariseau View Post

Another difference can show for folks with a 5.1 speaker configuration attached to a 7.1 capable AVR. DTS imposes different decoding rules for 7.1 tracks if the decoder knows the output is destined for 5.1 speakers. When you send the Bitstream, the AVR doing the 7.1 to 5.1 decode is burdened with those rules. But when you send LPCM, the OPPO sees the AVR as accepting 7.1 input and thus does a "normal" 7.1 decode to LPCM (which the AVR then down-mixes to 5.1 speaker output). SO, it is possible to perceive a quality difference between the 7.1 to 5.1 DECODE and the 7.1 decode in the OPPO followed by the subsequent DOWN-MIX to 5.1 in the AVR.
Does it work that way when a 7.1 capable AVR is configured for 5.1? I assumed the HDMI handshake would negotiate a 5.1 connection when the AVR is configured that way and the DTS decoder in the player would do the same metadata driven downmix as the AVR. But, if the player produces a 7.1 PCM output that the AVR has to independently downmix, then bitstream would be the better way to go.

So, what happens when the player decodes a 5.1 DTS track for PCM output to a 7.1 receiver that's configured for 5.1? Does it do the DTS mandated expansion to 7.1, which the AVR then has to downmix back to 5.1? That would not be good since DTS Essential channel expansion duplicates the surrounds to the rears and it's unlikely that the AVR downmix would produce the same result as the original 5.1 mix.
post #25315 of 26645
I don't know of any AVRs which limit their HDMI LPCM input to 5.1 because the user has specified a 5.1 speaker output configuration. Generally speaking the AVR wants ALL the content -- intending to handle it from there. Keep in mind such a limitation would also affect LPCM and decoded TrueHD 7.1 tracks.

The DTS expansion to 7.1 is a weird one. Players that do that for their Analog outputs still send only 5.1 LPCM as decoded HDMI output. Go figur.... DTS is nothing if not inconsistent. (Technically this is all tied up in the arcane rules for "alternate speaker presentations" -- i.e., physical speaker positioning -- with differing default locations for the Side Surround speakers in 5.1 and 7.1 speaker configurations.)
--Bob
post #25316 of 26645
Quote:
Originally Posted by Bob Pariseau View Post

The bottom line is, don't accept any glib answers here. Try both ways -- watching out for volume differences, and limitations (gotchas!) imposed by the implementation -- and use whichever one YOU like. If you can't hear a difference, and don't care about leaving Secondary Audio ON in the OPPO, and aren't blocked by processor implementation gotchas, then go ahead and use Bitstream, as it has the important added advantage of allowing your AVR to light up its DTS-HD MA or Dolby TrueHD input format lamp on the front panel. And we all know audio sounds better when those lamps are lit. biggrin.gif
--Bob

Ah yes, psychoacoustics! I get the same effect when I look at my 3/4 inch thick Audioquest speaker cables laying across the hardwood floor. smile.gif
post #25317 of 26645
Thanks, Bob. I am still using an older non-HDMI receiver and can't test that myself. So, I guess my assumption about the extent of the HDMI handshake was mistaken. And, yes, DTS does some oddball stuff with Essential decoding and speaker re-mapping.
Edited by BIslander - 6/29/13 at 9:34am
post #25318 of 26645
It might help to keep in mind that THE ORIGINAL CONCEPT for Blu-ray was that decoding would always be handled in the player. ALWAYS. As for example with the original Sony PS3.

This was necessary for Secondary Audio mixing to work right -- a fundamental distinguishing feature between Blu-ray and SD-DVD. (The primary track has to be decoded before audio mixing can happen, and all that has to happen inside the PLAYER.)

The concept of putting decoders in AVRs (for decoding of new, "lossless" Bitstream input formats) was tacked on as an after-thought when the manufacturers of the AVRs got miffed that they couldn't use in-AVR decoding as a way to push people to throw away their existing, perfectly good, HDMI LPCM input AVRs or multi-channel Analog input Receivers fast enough. The AVR guys got a big boost in this, because DTS-HD MA decoding in Blu-ray players turned out to take more horsepower than DTS had let on. Pioneer even had to discard a product cycle of players when they learned the designed-in processor couldn't actually handle the intense workload DTS was requiring. AVRs on the other hand can spread the cost of DSP power over multiple uses. Anyway, decoding in AVRs got established basically because, at first, the players could not decode DTS-HD MA, but the AVRs could.

Again, it wasn't SUPPOSED to be that way.

This is VERY DIFFERENT approach from the design philosophy behind SD-DVD, where the decoding was SUPPOSED to happen in the AVRs -- because this was before HDMI -- and S/PDIF (Digital Optical/Cox audio connections) could only carry STEREO LPCM. For digital multi-channel you needed to use a Bitstream over Optical/Coax -- which meant the AVR had to do the decoding. Then fancier (more expensive) SD-DVD players added in their own decoding for multi-channel ANALOG output. Then upscaling SD-DVD players added HDMI and now they COULD send multi-channel, high bit-rate LPCM using their new, built-in decoders.

These are fine examples of an industry truism: Generally speaking the consumer electronics industry is always happiest if they can find multiple ways to make you pay for the SAME functionality. Think of upscaling SD-DVD players connected to HDTVs which also had to include their OWN upscaling. But again, the original goal for Blu-ray was for the players to do the decoding. DTS being so late to the party changed all that.
--Bob
post #25319 of 26645
Quote:
Originally Posted by Bob Pariseau View Post

Barring bugs in either device, correctness (e.g., quality) of the decode is not the issue.

My preference for using LPCM is that it allows me to leave Secondary Audio ON without having to worry about the quality loss that results from RE-encoding the audio back into a (lossy) bitstream for output.

If you look at oddball cases in the formats, for the 93/95 there's actually a preference for using Bitstream. For example, the rare DTS-HD MA 5.1 192KHz format (found on some music discs) can not be decoded as 192KHz in the 93/95. The LPCM output is 96KHz. But the Bitstream output carries the full 192KHz in case the AVR wants to take a stab at decoding that (many AVRs of that vintage ALSO have the limitation to 96KHz for that). In the legacy lossy formats, some matrixed Rear channel info (e.g., DTS-ES) does not get decoded in the 93/95, but gets passed in the Bitstream. These are all remnants of the "DTS Essentials" decoder that DTS was licensing for Blu-ray players back when the 93/95 came out.

That's no longer happening, so the 103/105 don't have such oddball case limitations.

Barring both bugs and the oddball cases, if you are hearing a difference between LPCM and Bitstream, odds are there is a small VOLUME difference between the two decodes (and the subsequent processing path for both). Even a fraction of a dB Volume difference will be sensed as the "louder" one is the "better" one. Another difference can show for folks with a 5.1 speaker configuration attached to a 7.1 capable AVR. DTS imposes different decoding rules for 7.1 tracks if the decoder knows the output is destined for 5.1 speakers. When you send the Bitstream, the AVR doing the 7.1 to 5.1 decode is burdened with those rules. But when you send LPCM, the OPPO sees the AVR as accepting 7.1 input and thus does a "normal" 7.1 decode to LPCM (which the AVR then down-mixes to 5.1 speaker output). SO, it is possible to perceive a quality difference between the 7.1 to 5.1 DECODE and the 7.1 decode in the OPPO followed by the subsequent DOWN-MIX to 5.1 in the AVR. (With EITHER WAY possibly being perceived as "better"!)

There are also cases of lesser quality AVRs which handle HDMI LPCM input poorly. I.e., they don't buffer and re-clock it to make sure the data is properly transferred. With Bitstream input, the AVR isn't faced with having to do that, and so they can get away with cutting that particular corner. If your AVR offers adjustable lip-sync delay which functions when using HDMI LPCM input, then it has to buffer and re-clock. If not, then maybe they cut that corner and Bitstream input will be "better" because LPCM input is not being handled properly.

And as mentioned above, there are also cases of AVRs that don't have enough horsepower to decode all the various Bitstream input formats *AND* provide processor intensive audio processing such as Room Correction.

Confused yet?

The bottom line is, don't accept any glib answers here. Try both ways -- watching out for volume differences, and limitations (gotchas!) imposed by the implementation -- and use whichever one YOU like. If you can't hear a difference, and don't care about leaving Secondary Audio ON in the OPPO, and aren't blocked by processor implementation gotchas, then go ahead and use Bitstream, as it has the important added advantage of allowing your AVR to light up its DTS-HD MA or Dolby TrueHD input format lamp on the front panel. And we all know audio sounds better when those lamps are lit. biggrin.gif
--Bob


Does having the secondary audio on limit the main soundtrack in any way, as far as quality and different sound modes? Other than having commentary mixed in are there any other advantages to leaving this on?
post #25320 of 26645
^ These days, Secondary Audio is used for some (but not all) Picture in Picture Commentary tracks and for Menu Sound Effects. It's only ever found on Blu-ray discs. The way Blu-ray works, if a disc has ANY Secondary Audio, and Secondary Audio is enabled in the player, then the player has to decode the primary track EVEN IF the user hasn't actually chosen any playback options that use Secondary Audio. (Technically this is because BD-Java code on the disc might start up Secondary Audio without giving the player any warning -- Blu-ray certification tests exist for this.)

With Bitstream output set in the 93/95, the player then has to RE-encode the audio back into a Bitstream for output. No consumer gear has the horsepower to encode a lossless Bitstream on the fly, so a lossy Bitstream format is used. It's the highest bit rate lossy Bitstream but still lossy. It's also a 5.1 Bitstream, even if the primary audio is 7.1 or 2.0.

SO, if you are using Bitstream output you should leave Secondary Audio OFF except when you actually WANT to use a disc feature that needs it.

For LPCM output on the other hand you can just leave it ON.

If there's no actual Secondary Audio being mixed in, then the decoded LPCM is output unmolested.

If there IS Secondary Audio being mixed in, then the mix settings imposed by the disc typically attenuate the primary track while Secondary Audio is happening, so the quality is not really relevant. But Secondary Audio is just stereo 16-bit, so it mixes in easily.

SO, if you use LPCM output in the 93/95 you can leave Secondary Audio ON. And then choose to hear it or not via the choices you make on the disc itself.
--Bob
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