MQA and DRM - an opinion from the EFF

Saw this MQA-related article last week and was surprised I had not come across it here first!

I generally steer clear of MQA debate threads and am not looking to stir the MQA pot, just thought I would post the link.

(…quickly and quietly backs away from thread…:wink:)

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I have always viewed MQA as a vast, right wing conspiracy. Thanks for the article.

Ha, too late for that.

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Oh, yeah? Well, they know EFFing nothing about experiencing high end audio.

In before the MQA apologists arrive…


MQA already have ‘DRM framework’ embedded into all MQA files, it will depend on the music labels to incorporate their proprietary DRM into it. Obviously with this infrastructure in place, I’ve no doubt the music labels already have taken advantage of it long time ago.

MQA can still be copied and share just like normal music files but are they can be tracked with cryptography signatures embedded inside the files. Any tempering to the file, such as extracting or modify to the file information will render it undecoded when playback. In some cases it can limit the playback quality when unlicensed devices are used.

I am confused. All this talk of “trojan DRM” at some point in the future. Don’t Tidal (and all the streaming services) already use DRM? How otherwise could I download the files locally, but lose access to them when I cancel my subscription. Perhaps I am the last person to find out about some clever way to get around this? Otherwise the DRM seems to be pretty robust.

Does anyone know what kind of DRM encapsulation streaming service use and does anyone know if/how it affects the sound? I must confess I have not heard much sound difference between my old CD rips and Tidal FLAC versions of the same albums.

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Streaming services use encryption on the downloaded tracks and your authentication (login) with the service gives you the right to decrypt assuming your account’s in order. This is a form of DRM, but it’s understandable as they need to ensure only subscribers get to listen. The streaming services often offer subscription tiers depending on quality so authentication with a lower-tier subscription might also restrict the quality available. This should be the only affect their “DRM” has on sound quality.

I’ll not labour the MQA DRM point, you can see my thoughts here on an MQA thread. If you don’t own licensed hardware then there’s no access to the best quality copy.

Whether anyone can reliably tell the difference between Redbook CD, hi-res FLAC or MQA streams is open to debate (lots of it). Using my own reference tracks, I can spot the difference between MP3 and CD as well as Bluetooth and CD (though that can be harder). I’ve never convinced myself that I hear a difference between Redbook and hi-res…

No, no it isn’t.

From the article -

So I’d agree with your point (streaming might not be, it’s just encryption) but the DRM definition provided isn’t great. The quote says “typically” and the bold text’s your own highlight. The Wikipedia article is a better starting point and I’d argue makes your assertion look less certain.

Unfortunately DRM with MQA is no fiction:

I copy/paste from an article from Arstechnica:

To complete the MQA encoding, a reversible lossless digital watermark is embedded all the way through the resulting file. Crucially this includes instructions to the decoder for which of several decoding methodologies should be used to unfold and play the file. MQA Ltd requires licensees of its technology to use an HSM (Hyper-Security Module) that issues encrypted signatures contained within each file.

This watermark also includes unique ISRC tags describing the song, composer, copyright, etc. When the watermark has been successfully recognised and decrypted a little green or blue LED will light on the user’s MQA decoder to signify authenticated playback.

Key technologies in the MQA system are described in detail in several patents awarded to Bob Stuart, mathematician Peter Craven, and other collaborators: Doubly compatible lossless audio bandwidth extension, which discusses the legacy compatibility through noise-floor hiding; Digital encapsulation of audio signals describes convolving a non-minimum phase IIR filter for the downsampling process, followed by minimum-phase IIR filter when later up-sampling, in order to “deblurr” the smear of digital filters; Versatile music distribution explains a DRM scheme to distribute dual-purpose music files, such that licensed key holders gain access to the original hi-res quality, while unlicensed users only hear a lo-res version.

The latter patent highlights various ideas for encrypting song keys with user and device keys, enabling online servers to provide downloads and streams only to authorised customers. It explains how to deliberately degrade PCM audio by adding noise, for example, although MQA in its final release does not do this, instead allowing downsampling and requantisation to create a universal playback version that’s audibly inferior to the original hi-res audio. A related patent Lossless buried data outlines how to hide data in music, in a reversible process that depends upon presenting a cryptographic key such as an encrypted certificate to read.

The original can be found here

The patent he refers must be this one: Transparent lossless audio watermarking enhancement

Correction: It is this one Versatile music distribution


OK, that was the first definition I came to that addressed the point I wanted to present. :neutral_face:

From the Wiki you referenced above -

From the Wiki article on watermarking -

I think these are the DRM methods that scare people in the context of MQA, in that the original signal is ‘corrupted’.

I agree with you, in that the law hasn’t caught up with the technology.

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MQA does not disable illegal distribution. MQA does not have phone home DRM. This copy protection cannot be added in the future without breaking most of the existing MQA hardware without a network port.

You can freely copy MQA files (e.g. from free 2L download, MQA file purchases, MQA CD rips) and they will play on MQA DAC, or be MQA Core decoded using Roon or Audirvana.

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The quote you reference was about DRM, in general. The quote wasn’t directly about MQA.

You speak of the present. I speak of the future.

Or a firmware update?

I hope these fears about MQA DRM have as little likelihood as the sky falling.

If music publishers embrace MQA, then they are doing it for only one reason and it isn’t for SQ.

I’m glad you have replied to me. It gives me a chance to, once again, ask this -

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If Tidal protect downloaded music files (on your phone , say) why can’t I just “ignore” the play header and play files forever. The fact that I can’t suggests that they have already developed a highly secure functional “DRM / do not copy” method already. Perhaps they don’t need another to continue to lock down their music. So were Tidal to offer, say 24/96 music files they would also be unplayable/uncopyable without an active Tidal subscription. It looks to me like the DRM/Do not copy/ control your version horse has bolted… what am I missing here?

There’s software out here that will let one do just that.

MQA on media, i.e. CDs.

It isn’t a coincidence that Tidal, who has begun loading it’s service with only MQA versions, lets one download selections on a limited basis. I suspect the promise of Tidal eventually having some sort of MQA DRM was a requirement of the music houses that supply Tidal before Tidal could supply this type of download. An MQA DRM on all Tidal selections will just tighten this up further. Dunno.

Does Qobuz, without MQA selections, offer the same download opportunity? Dunno.

I seem to remember that, when MQA first came out, its raison d’etre was for more economical downloads.

That was stage 1. Stage 2 was that MQA ‘improved’ SQ. Stage 3 has yet to happen.

Your observation about how Tidal works now with some sort of DRM just underlines the inevitability of stage 3.

If you can embed a user-specific and/or device specific watermark in the file at time of purchase, as long as the mqa decoder/renderer checks these, they can prevent playing of the file if not correct. This is easily doable and as a matter of fact was standard in the early days of download stores when everything was drm’d (although the watermark tech was pretty lame back than). You would need a one time registration process for the devices that would decode/render mqa files so they would know it’s you when it sees user/device watermarks in mqa files – but you do not need any ongoing “phone home” to implement drm in mqa files.

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Hmmm, embed a user specific watermark in MQA CD that can be bought physically in a retail store? I need to exit this thread.

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Hmm back at you :slight_smile: I was talking about MQA downloads. You are right about an MQA CD. What I said wouldn’t work for that…