MQA is Vaporware

[Ralf11]

2 hours ago, vmartell22 said:

It would be better for the general public if the prevalent platform would not be DRM infected.

 

 

 

 

Very true.  He is now arguing that a small amount of DRM is not so bad, like a parasite with reduced virulence.

 

It would be better for the general public if the public would not be flu virus infected.

[Ralf11]

1 hour ago, Don Hills said:

 

The [larval stage]  is present in all MQA files.... I believe it'll play out [so there is] No enforcement of rights in the initial stages until the [parasite] becomes ubiquitous [and has infected the entire population], then increasing enforcement [to deflect a stream of resources form the host organisms]. 

 

As for revenue stream, it's not so much about revenue. It's about control. The [parasites'] loss of [resources is] being caused by a loss of [genetic] control [of the host organism]. They want the control back [and will try to insert their genes into the host genome].

 

[Lee Scoggins]

8 minutes ago, opus101 said:

 

Are you aware that it isn't PWM?

 

I meant sigma-delta modulation.  It’s late here in Atlanta and I am tired.

[Lee Scoggins]

6 minutes ago, Ralf11 said:

 

 

Very true.  He is now arguing that a small amount of DRM is not so bad, like a parasite with reduced virulence.

 

It would be better for the general public if the public would not be flu virus infected.

 

That’s not what I said at all.  I said MQA encryption is part and parcel of the folding.

If you take the view that any encryption is DRM then you are being irrational.

[opus101]

2 minutes ago, Lee Scoggins said:

 I said MQA encryption is part and parcel of the folding.

 

I can't see how this can be, would you be able to explain? Seems that we'd need noise-like characteristics for the lowest 8 bits so that undecoded playback isn't affected much (though truncation to 16bits would probably work even better) but how does folding entail encryption?

[firedog]

8 hours ago, Lee Scoggins said:

Looks like another writer also believes the mobile market is where the action is.

http://audiophilereview.com/audiophile/audiophiles-are-not-the-future-for-mqa.html

And? 

We all realize there is a likelihood that streaming is the future of mainstream audio. Big insight.

 

Yet you've still never answered the question of why MQA is needed at all for this - since hi-res and higher quality files can be streamed with the same bandwidth as MQA. Just because you keep repeating that MQA saves bandwidth doesn't make it true.

 Younger people so far have shown little inclination to pay for streaming and especially premium streaming.... How does MQA change this in a way that streaming other high quality files doesn't?

 

Obviously if the labels move to only licensing MQA and mp3 for streaming, they will make money from it. That's where the DRM comes in, but that's an issue you keep ignoring.

[Fokus]

4 hours ago, vmartell22 said:

The stated intent is MQA everywhere. Now I feel compelled to fight it with all my heart - In fact I do believe that discussing the the technical minutia is pointless - this is an idea that is rotten in principle. A transparent attempt to take away consumer rights. Whether it sounds good, OK or  bad is immaterial . The  intent is rotten at the core. 

 

Yes. Breaking down MQA technology is intellectually pleasing, a fun game. But it is not really necessary.

 

Fighting MQA politics is what matters.

[firedog]

4 hours ago, Lee Scoggins said:

Still researching but my current understanding is that DRM isn’t being used on MQA 

files presently so I am not sure how any consumer freedoms are being harmed.

 

And still no one has clearly explained a revenue model from DRM, which is one reason I suspect its not a factor in the label support.

 

1. Stop with the incorrect understanding that DRM means copy protection. If you incorrectly make that assumption, you come to the incorrect conclusion about MQA and DRM that you keep erroneously repeating.

2. Check the patents. DRM is there. 

3, The possible revenue models for MQA and DRM have been mentioned here multiple times - you just keep ignoring them.

[Fokus]

3 hours ago, opus101 said:

Its important to recognize that this ringing isn't a given. There's the theoretical possibility of ringing because of the steepness of the AAF, but to get ringing in practice you need to have frequency content at the ringing frequency

 

Of course.

 

But in MQA's view the ringing is a given. After all, they are the Ring Busters.

 

That they are contradicting themselves is a small detail ...

 

[firedog]

6 hours ago, Lee Scoggins said:

 

My guess is that if MQA is in their hardware and streaming services, they may not care about any DRM if they get the music on their phones with a big library for a reasonable price.

They already get that without MQA, which somehow you miss.

[firedog]

2 hours ago, Lee Scoggins said:

That is a bit like saying we don’t like DSD because it is sigma-delta modulation.

No, because it isn't a closed proprietary format like MQA is.

[Shadders]

16 hours ago, Fokus said:

(and f...ing please go and read the AES papers, instead of coming here with new fabrications every time),

Hi Fokus,

As per your comment, i have read the literature : http://www.aes.org/tmpFiles/elib/20180113/17501.pdf

 

Section 4.1 lists the relevance of the Dragotti paper - page 9.

 

Therefore my referral to the wiki is correct.

 

Have you challenged the AES with their mistake in endorsing the MQA paper ?. That is, the MQA paper in listing and stating the MQA process uses the Dragotti paper (and others), is a false statement by MQA ?.

 

Have you written to MQA (Bob Stuart and Peter Craven e-mail address is on the paper) to notify them of this mistake ?

 

Thanks and regards,

Shadders.

[Shadders]

16 hours ago, Fokus said:

Given a 192kHz recording. It will have ringing at 96kHz, because it has been produced with an industry-standard half-band AA filter in the ADC.

 

MQA will downsample this to 96kHz. After all, 96k is all that can pass through their pipe.

For this operation they do not select a standard AA filter, but a tailored one. Their filter will reach null at 96kHz (to kill the recording ADC's ringing), but otherwise it will be very leaky, i.e. it causes aliasing in the target 0-48kHz band.

Hi Fokus,

I am new to DSP aspects here - so i have a few questions.

 

When i examine the spectrums of those presented in Hifi News, i do not see the energy spike which would be the ringing of the filter used in the ADC.

Why is that ?

 

Why is the ringing exactly at 96kHz, if the ADC filter cut off is at perhaps 86kHz ? (or another value)

 

Regards,

Shadders.

[Hifi Bob]

21 minutes ago, Shadders said:

When i examine the spectrums of those presented in Hifi News, i do not see the energy spike which would be the ringing of the filter used in the ADC.

Why is that ?

 

Because it’s a problem that doesn’t exist with real-world speech/music signals and real-world ADC implementations.  As you pointed out earlier, if there was a real problem with digital, one of the big boys (Sony, etc.) would have addressed it years ago. At the very least, it would have been a known problem, discussed in music (especially classical) journals.

[Fokus]

17 minutes ago, Shadders said:

When i examine the spectrums of those presented in Hifi News, i do not see the energy spike which would be the ringing of the filter used in the ADC.

Why is that ?

 

Why is the ringing exactly at 96kHz, if the ADC filter cut off is at perhaps 86kHz ? (or another value)

 

1) because 'ringing' is not a distortion of the system's frequency curve or steady state signal spectrum. It can only be seen in amplitude-versus-time, or (slightly) in spectrum-versus-time.

 

2) the majority of ADCs are half-band and thus cut at (about) 96kHz.

 

If in discussions like these we would have to cover all options, possibilities and eventualities then posts like these would be 768 lines long and would come with a disclaimer and legal scrutiny before posting.

 

3) As for challenging the papers. Why??? It is not even a given that these were ever reviewed before acceptance. I don't know the standards for AES journals.

 

When I started my academic carreer the first advise I got was: and remember, papers are mostly lies. It is even worse today than back then. This said, I never knowingly lied in any of my papers ;-) Also not implying that MQA are lying. Just telling you that a paper is not necessarily authoritative.

 

MQA may or may not use a triangle in some cases. That is not important. What is important is that these filters are leaky, and that MQA count on the aliasing falling below the noise. The triangles are not magic, the theory in the Dragotti paper bears no relevance to audio, and the blurring on the image in the D paper has nothing to do with the blurring of an audio master in the MQA story. That's why these are red herrings. It all looks impressive, but it has little or no relevance.

 

As an aside, bringing lore from image processing to audio is generally a bad idea. Image processing is resource constrained, audio processing is not. Therefore much of what happens in image processing is about efficiency and finding computational shortcuts, not about absolute quality of result. In audio you can run a Sinc filter. In imaging not even remotely.

 

 

 

Am I at 768 yet?

 

 

[Shadders]

2 minutes ago, Fokus said:

 

1) because 'ringing' is not a distortion of the system's frequency curve or steady state signal spectrum. It can only be seen in amplitude-versus-time, or (slightly) in spectrum-versus-time.

 

2) the majority of ADCs are half-band and thus cut at (about) 96kHz.

Hi Fokus,

If the ringing can only be seen in the time domain, then that means that the ringing energy is in the signal.

 

That then means the FFT will extract/present this energy at the frequency of the ringing. So we should see it - it will be in the FFT output.

 

Why do we not see it in spectral plots as per Hifi News or others ?

 

Regards,

Shadders.

[Shadders]

12 minutes ago, Fokus said:

3) As for challenging the papers. Why??? It is not even a given that these were ever reviewed before acceptance. I don't know the standards for AES journals.

 

When I started my academic carreer the first advise I got was: and remember, papers are mostly lies. It is even worse today than back then. This said, I never knowingly lied in any of my papers ;-) Also not implying that MQA are lying. Just telling you that a paper is not necessarily authoritative.

Hi Fokus,

What evidence do you have that MQA have NOT implemented the process/algorithm as per the Dragotti paper ?

Thanks and regards,

Shadders.

[Hifi Bob]

Have you read this paper? https://www.xivero.com/downloads/MQA-Technical_Analysis-Hypotheses-Paper.pdf

See esp. §5.3.

[Shadders]

12 minutes ago, Fokus said:

MQA may or may not use a triangle in some cases. That is not important. What is important is that these filters are leaky, and that MQA count on the aliasing falling below the noise. The triangles are not magic, the theory in the Dragotti paper bears no relevance to audio, and the blurring on the image in the D paper has nothing to do with the blurring of an audio master in the MQA story. That's why these are red herrings. It all looks impressive, but it has little or no relevance.

 

As an aside, bringing lore from image processing to audio is generally a bad idea. Image processing is resource constrained, audio processing is not. Therefore much of what happens in image processing is about efficiency and finding computational shortcuts, not about absolute quality of result. In audio you can run a Sinc filter. In imaging not even remotely.

Hi Fokus,

If MQA are using a triangle kernel, and this is not taken into account in your analysis of MQA, then your analysis is insufficient ? You are missing something ?

 

Although image processing such as a filter may be a 2D spatial process, the edge enhancement, or deblurring, still happens in both dimensions - X and Y. So, is it not therefore possible to adapt a 2D algorithm to a 1D domain, such as an audio file, to implement the same process (albeit adapted) ???

 

As you have admitted, you do not know what the internal MQA processes are (black box), so maybe you cannot state MQA does not use the Dragotti paper etc.

 

Regards,

Shadders.

[opus101]

1 hour ago, Fokus said:

But in MQA's view the ringing is a given. After all, they are the Ring Busters.

 

Right. So let's see if Lee can have a shot at answering this point. @Lee Scoggins, are you following along? You've already said you believe our view (that would be mine and Fokus' view, along with Bruno and most probably Rob Watts, I see esldude has 'liked' my comment so let's include him too) is mistaken, how have we mis-grasped this please?

[Shadders]

Hi Bob,

Thanks - i have not seen, but as per first few paragraphs, there is no energy at the cut off frequency of the filter - so ringing does not occur in the real world. I will read more thoroughly later - thanks

Regards,

Shadders.

[Don Hills]

5 hours ago, Lee Scoggins said:

 

Don, 

 

I understand that but isn’t it unfair to criticize MQA for encryption when that is a key part of the folding?  That is a bit like saying we don’t like DSD because it is sigma-delta modulation.

 

And your comment about control doesn’t work because it doesn’t explain where revenue growth happens.

 

It's not a key part of the folding. You can achieve the same result (reversibly converting the "folded" part to pseudo-noise so as to hide it under the 0-24 KHz signal) without encryption.

 

MQA works like HDCP. You can copy the source file freely. But you can't play it at full resolution without the licensed decoder.

[FredericV]

1 hour ago, Fokus said:

MQA may or may not use a triangle in some cases. That is not important. What is important is that these filters are leaky, and that MQA count on the aliasing falling below the noise. The triangles are not magic, the theory in the Dragotti paper bears no relevance to audio, and the blurring on the image in the D paper has nothing to do with the blurring of an audio master in the MQA story. That's why these are red herrings. It all looks impressive, but it has little or no relevance.

 

They needed something to also sell it to audiophiles. Any audiophile would dismiss MQA as a lossy MP3 alike quack format. So they added the false claim that it is authenticated (it's not, check Brian Lucey), that it sounds exactly like in the studio (it's not, MQA is not an internal format in the studio) and can undo blur (which so far has not been proven by MQA).

Unless you call upsampling with minimum phase and one cycle of post-ringing deblur.

[Don Hills]

5 hours ago, Lee Scoggins said:

 

I don’t believe this is how it works.

 

Opus101's description is considerably simplified but correct.

Try this:

https://en.wikipedia.org/wiki/Ringing_artifacts

 

If you prefer your education in video form, start here:

https://www.youtube.com/watch?v=FG9jemV1T7I

You may find the section from 3:00 to 16:00 most relevant.

Next, go here:

https://www.youtube.com/watch?v=cIQ9IXSUzuM

I strongly recommend watching the whole video. Pay particular attention from about the 17:20 mark.

 

The tl;dr summary: "Ringing" happens when the filter has to cut off energy at or above its cutoff frequency.  Good luck trying to find a musical instrument that produces any significant energy above 96 KHz, and even more luck finding a microphone capable of recording it.

 

 

 

[psjug]

Archimago's recent blog entry on "ringing" 

http://archimago.blogspot.com/2018/01/audiophile-myth-260-detestable-digital.html