DVD Audio extractor ripping rears at different volume levels?

[ssully]

Here is our Oppo 105D Setup Menu interface and the setup options that clearly pertain to audio...

View attachment 77012 View attachment 77013 View attachment 77014

From your user manual:

This is pertinent if you are using an HDMI connection
Bitstream = raw data output, your AVR decodes the raw DTS or Dolby audio bitstream. None of your other Oppo setting will affect it.
LPCM = decoded output, your Oppo decodes the bitstream before sending to the AVR. Other Oppo settings can affect it.

Yours is set to 'Auto'. I have no idea whether it's outputting Bitstream or PCM.

This is pertinent if you are using coax/optical connection:

Yours is set to 192k LPCM, which means it is decoding Dolby and DTS audio to PCM (think "wav" audio) before sending it to the AVR. It is also downmixing all DTS and AC3 surround to 2-channel, because this connection cannot pass more than 2 channels of PCM audio. It is also possibly resampling the decoded DTS/AC3 audio to 192 kHz, though I might be misinterpreting this, it claims not to upsample anything. If it is not resampling,. the decoded DTS/AC3 audio PCM format should be 48 kHz/24 bit . Other Oppo settings can affect the output as well.

 

[ssully]

I understand what the OP is trying to do, but not what the OP is trying to accomplish. Why does the OP want to do this? As you imply, it can be apples and oranges - DTS vs MLP can be different mixes and/or masterings.

I've never found that to be true. The only differences I've seen , in audio file analysis, is in LFE levels and bandwidth restrictions, both a consequence of DTS/Dolby lossy encoding standard practices rather than mastering per se. The mixes themselves on the same disc are never different.

 

[ssully]

Hope I'm not muddying things up here:
Of the streams on a DVD-A disc,
MLP is the highest resolution and with few exceptions is the preferred stream to rip and convert to FLAC.
DTS is lower resolution.
Dolby (AC3) is lowest.

Not really. You can't simply map lossy bitrates to 'resolution' as you can with PCM bit depths.

 

[ssully]

Hey, no problem, really glad I could help a little. I'm still wondering why the Oppo had no choice for MLP playback (from the disc) in the setup.

It does. In his Oppo Settings, DVD-Audio Mode is set to 'DVD-Audio'. That means it will default to MLP playback.

 

[ssully]

Indeed and agreed...

Personally I don't bother re-encoding dts audio streams (from dts-CD's or DVD's) to FLAC. Plus the FLAC files end up being bigger.

Only slightly -- the increase from the added FLAC metadata.

(Unless you mean a bitstream file versus decoded file ...sure, the .wav and FLAC files made from the .wav will be bigger than the raw. *.dts file)

 

[jimfisheye]

If you want to compare files - ie. critically compare for 1:1 bit accuracy - do it with a computer. Removing other variables is critical or you'll go in circles. And you need a source file for reference or it's just speculation! Hence my suggestion to burn your own disc and rip it back if you want to pursue this.

Check out the lesser audio streams meant for less compatible older equipment if you wish just to look for an easter egg as it were. If they're the same, rip the lossless one.

That's the way to keep this simple.

 

[B&W Driver]

This is pertinent if you are using an HDMI connection
Bitstream = raw data output, your AVR decodes the raw DTS or Dolby audio bitstream. None of your other Oppo setting will affect it.
LPCM = decoded output, your Oppo decodes the bitstream before sending to the AVR. Other Oppo settings can affect it.

Yours is set to 'Auto'. I have no idea whether it's outputting Bitstream or PCM.

This is pertinent if you are using coax/optical connection:

Yours is set to 192k LPCM, which means it is decoding Dolby and DTS audio to PCM (think "wav" audio) before sending it to the AVR. It is also downmixing all DTS and AC3 surround to 2-channel, because this connection cannot pass more than 2 channels of PCM audio. It is also possibly resampling the decoded DTS/AC3 audio to 192 kHz, though I might be misinterpreting this, it claims not to upsample anything. If it is not resampling,. the decoded DTS/AC3 audio PCM format should be 48 kHz/24 bit . Other Oppo settings can affect the output as well.

SSully .... Being old-school stereo folks, our equipment is pretty much set up in analog mode. In other words, our interconnects are RCA. We only use HDMI in our [temporary] quad setup for the Oppo's video interface. The Oppo 105D has multichannel (MC) RCA outputs, we have RCA cabling, so we go with what we have.

As for the second menu you highlighted... Assuming that RCA is a form of "coax," I suppose this might be an important thing to consider? On the other hand, we've been testing and playing MC music, off and on, for roughly a year now, so how can a "downmix" to 2-channel (stereo) be occurring. Once again, as a layman, this doesn't make much sense to me. No doubt, this is another one of those things that we need to learn more about.

 

[ssully]

So one conclusion that can be made, now that I understand what MLP is, is that DVDAE is defaulting to a "better" source, right?

You see, when the layman plays a DVD-A and sees that the only options are Dolby Surround or DTS Surround, it becomes a pretty simple choice based on what sounds better to the listener. How would a layman know that there's something buried in the "AUDIO_TS" directory that's called "MLP"?

Anyway, if DVDAE is defaulting to better audio information, we'll go with that.

Your Oppo is set to default to 'DVD-Audio' for DVDA discs, so I don't understand why the *player* would only offer you Dolby or DTS surround. I wonder if it is somehow also defaulting to 'stereo', in which case it might be doing some arcane processing (MLP surround--> downmix to stereo --> upmix with Dolby or DTS surround upmixer--> multichannel PCM out) EDIT: this doesn't seem likely, but....

 

[Beefalo]

Some of us only know the basics of the digital multichannel alphabet soup, and this is the primer I needed..did I say Thank you?

 

[LuvMyQuad]

On the other hand, we've been testing and playing MC music, off and on, for roughly a year now, so how can a "downmix" to 2-channel (stereo) be occurring. Once again, as a layman, this doesn't make much sense to me. No doubt, this is another one of those things that we need to learn more about.

Be sure both the Oppo and the AVR you use are both set for 5.1 channels.

 

[ssully]

SSully .... Being old-school stereo folks, our equipment is pretty much set up in analog mode. In other words, our interconnects are RCA. We only use HDMI in our [temporary] quad setup for the Oppo's video interface. The Oppo 105D has multichannel (MC) RCA outputs, we have RCA cabling, so we go with what we have.

As for the second menu you highlighted... Assuming that RCA is a form of "coax,"

It's not, in this context.

If you are accessing the MLP layer of your disc, the output is multichannel PCM to your AVR. Your Oppo is set to access the MLP layer by default.

If you are accessing the DVD layer of your disc, the Oppo is certainly decoding DTS or Dolby (AC3) audio to multichannel PCM before output. Otherwise you would hear only white noise.

NB your manual says
Availability of languages and audio channels varies by disc. Some DVD-Audio discs allow audio track selection with the AUDIO button, while others require the user to choose from the audio setup menu of the disc.

I am assuming your Oppo is configured for more than 2 speakers and otherwise configured correctly. Because you are using analog RCA connections, all the settings in Speaker Configuration apply to your output. This includes your downmix mode (a curious setting but it probably should be set to 5.1), speaker number, size, distance, crossover (yours is set to 40Hz, default is 80), upmixer (yours is set to DTS Neo: Music mode), dynamic range control (yours is set to ON), trim (per-channel level), output volume (variable or fixed).

NB: The BDP-105 supports up to 2ch/192kHz PCM signal through its USB audio input, and up to 2ch/96kHz PCM, Dolby Digital, DTS and AAC signal through its Optical and Coaxial audio inputs.


tl;dr - read your manual, carefully

 

[marcb]

Now you're comparing different sources while your ripping app is an unknown variable. (If we're entertaining the idea that DVDAE is corrupting files.)

Also there's the part where file corruption usually ends in dropouts. Not a volume attenuation that would have to be processed by specific digital audio handling code. That makes this kind of an extraordinary accusation. That's why it begs evidence.

By different sources, I meant the different file types/codecs.

So again, wouldn’t a simple null test be evidence if they are the same or not?

 

[marcb]

I've never found that to be true. The only differences I've seen , in audio file analysis, is in LFE levels and bandwidth restrictions, both a consequence of DTS/Dolby lossy encoding standard practices rather than mastering per se. The mixes themselves on the same disc are never different.

I have.

I’ve found them to occasionally have different songs lengths, different edits and clearly different compression/limiting on some channels. Now maybe the lengths/edits are due to authoring differences and the compression/limiting are due conversion differences (which is the point of the discussion, I suppose). But my educated gut tells me it’s not (however I’m not interested enough to put in the time and effort to confirm or deny).

 

[jimfisheye]

By different sources, I meant the different file types/codecs.

So again, wouldn’t a simple null test be evidence if they are the same or not?

Ah, OK. Simply yes.

If you had examples of lossy files or whatever kind of generation loss - as opposed to obvious different levels or a clearly different mix - those null tests usually result in a strong null down to around -90db. That still tells you that the files were probably the same upstream but there some generation loss or noise added now. Files that are the same audio but at a different volume level will have a difference result that is nearly full level audio. Full null and even nearly null results are never a coincidence.


Yeah, we were all just talking about that John Lennon 5.1 remix greatest hits collection not long ago that snuck the raw mixes out in the DD stream while the main lossless streams had the stepped on damaged mastering. Don't forget to look for easter eggs!

 

[B&W Driver]

Your Oppo is set to default to 'DVD-Audio' for DVDA discs, so I don't understand why the *player* would only offer you Dolby or DTS surround. I wonder if it is somehow also defaulting to 'stereo', in which case it might be doing some arcane processing (MLP surround--> downmix to stereo --> upmix with Dolby or DTS surround upmixer--> multichannel PCM out) EDIT: this doesn't seem likely, but....

SSully ... I'm happy that you went back to this because it really had me scratching my hat stand.

 

[quadsearcher]

Not really. You can't simply map lossy bitrates to 'resolution' as you can with PCM bit depths.

Correct. I knew that was incorrect usage (what's a better term? "quality"?) when I typed it, but I was helped by a similar description here in the forum when I was new, and though simplified, and with an incorrect term, I thought the usefulness of the comparison of streams outweighed inadvertent (slight) misinformation.
In other words, as a comparison, it stands, no? I just don't know what word or words should be used in place of resolution.
Is it MLP has a higher bitrate,
DTS lower bitrate than MLP,
and AC3 lowest bitrate?

Apologies for stepping on your thread, B & W, but I can't pass up a chance to improve my own understanding.

It does. In his Oppo Settings, DVD-Audio Mode is set to 'DVD-Audio'. That means it will default to MLP playback.

I think I get it, it was already going to play MLP, so no need for the menu to list that as a choice. Thanks.

 

[ssully]

I have.

I’ve found them to occasionally have different songs lengths, different edits and clearly different compression/limiting on some channels. Now maybe the lengths/edits are due to authoring differences and the compression/limiting are due conversion differences (which is the point of the discussion, I suppose). But my educated gut tells me it’s not (however I’m not interested enough to put in the time and effort to confirm or deny).

On the same disc, you've found these radical mix differences between the lossy and the lossless multichannel versions?

The only way I can imagine this happening is if the lossy version was a 'legacy' DTS or AC3 version taken from some earlier release.
Companies have literally no financial incentive to create different lossy versus lossless mixes for the same release.

I'd ask for an example, but you've already indicated one will not be forthcoming.

 

[SeeMoreDigital]

I would do this if I could, but my eqpt doesn’t seem to recognize .dts files.

I have muxed my .dts streams within the .mka container using MKVtoolNIX...

It can handle DTS CDs, but those are limited to 16/44. But most DTS programs on music DVDs is not 16/44.

Indeed, dts audio streams on DVD discs are encoded at 48.00kHz

 

[ssully]

Correct. I knew that was incorrect usage (what's a better term? "quality"?) when I typed it, but I was helped by a similar description here in the forum when I was new, and though simplified, and with an incorrect term, I thought the usefulness of the comparison of streams outweighed inadvertent (slight) misinformation.
In other words, as a comparison, it stands, no? I just don't know what word or words should be used in place of resolution.
Is it MLP has a higher bitrate,
DTS lower bitrate than MLP,
and AC3 lowest bitrate

Apologies for stepping on your thread, B & W, but I can't pass up a chance to improve my own understanding.

What you write above is true, but not the whole story.

For lossy codecs AC3 and DTS, which use psychoacoustic models, there is no simple relation between bitrate and audible quality. They also don't 'use' bits the same way. In fact they are hard to compare fairly. And in the few actual controlled listening tests, there's no clear winner, despite all the audiophile mythology about 'Dullby'.

As for MLP (lossless) vs lossy, there's also a knee jerk contention that lossy will sound worse. That too is highly dependent on conditions. Regarding lossy multichannel, note a general rule as per Dr. Toole that as you add channels from mono to stereo to multi, reliable discrimination of audio quality decreases. (It's why Toole/Olive's famous speaker preference studies used *single* loudspeakers)

I think I get it, it was already going to play MLP, so no need for the menu to list that as a choice. Thanks.

I haven't seen a screencap of the *disc* menu here so I don't know what it lists. The *Oppo* Settings menu has a 'DVD Audio Mode' setting where the options are 'DVD-Audio' and 'DVD-Video'. I don't know how easy it is to switch between them using the remote.

 

[ssully]

SSully ... I'm happy that you went back to this because it really had me scratching my hat stand.

Your Oppo has an intricate set of settings for downmixing and upmixing, that seem to apply only to the RCA outputs. I suggest you study the manual closely.

(Actually I suggest you just get a modern AVR with HDMI inputs)