Popular Post wgscott Posted October 11, 2018 Popular Post Share Posted October 11, 2018 In non-specialist terms, can someone explain how Digital Rights Management (presumably some sort of watermark or something akin to it) would work in the MQA codec? Also, if it replaces audible watermarks currently used in some streamed music, could that be a good thing? Let's have a dispassionate, deliberative discussion. Hugo9000, sphinxsix and jtwrace 2 1 Link to comment
Brinkman Ship Posted October 11, 2018 Share Posted October 11, 2018 Good idea for a thread... wgscott 1 Link to comment
jabbr Posted October 11, 2018 Share Posted October 11, 2018 Since the specification is secret and requires an NDA, there’s no way to really know what it does. Competant formats are open. That’s the only way they can demonstrate their competence. MikeyFresh 1 Custom room treatments for headphone users. Link to comment
Brinkman Ship Posted October 11, 2018 Share Posted October 11, 2018 1 minute ago, jabbr said: Since the specification is secret and requires an NDA, there’s no way to really know what it does. Competant formats are open. That’s the only way they can demonstrate their competence. ...we can good idea of how it works conceptually. Link to comment
Popular Post trappy Posted October 11, 2018 Popular Post Share Posted October 11, 2018 I have noticed that the MQA versions of some of the most obviously watermarked recordings (i.e older DG) do not exhibit watermarking signatures. Especially obvious when both versions are there. I’ll try to find an example later. I’m thinking the Chicago Abbado Mahler 5... No idea how it works... wgscott, wklie and crenca 1 2 Mac Mini (+Tidal +Roon) -> WiFi -> Lyngdorf TDAI1120 ->JM Reynaud Lucia (Tellurium Q Black v2) Link to comment
Popular Post jtwrace Posted October 11, 2018 Popular Post Share Posted October 11, 2018 I'm pretty sure it's like this: Open wallet Bend over Open wallet Repeat Sonic77 and MikeyFresh 1 1 W10 NUC i7 (Gen 10) > Roon (Audiolense FIR) > Motu UltraLite mk5 > (4) Hypex NCore NC502MP > JBL M2 Master Reference +4 subs Watch my Podcast https://www.youtube.com/channel/UCXMw_bZWBMtRWNJQfTJ38kA/videos Link to comment
Brinkman Ship Posted October 11, 2018 Share Posted October 11, 2018 5 minutes ago, jtwrace said: I'm pretty sure it's like this: Open wallet Bend over Open wallet Repeat ...dry, or lubed? Link to comment
jtwrace Posted October 11, 2018 Share Posted October 11, 2018 3 minutes ago, Brinkman Ship said: ...dry, or lubed? MQA, we take it anyway we can get it W10 NUC i7 (Gen 10) > Roon (Audiolense FIR) > Motu UltraLite mk5 > (4) Hypex NCore NC502MP > JBL M2 Master Reference +4 subs Watch my Podcast https://www.youtube.com/channel/UCXMw_bZWBMtRWNJQfTJ38kA/videos Link to comment
esldude Posted October 11, 2018 Share Posted October 11, 2018 From Lee Scoggins in the other thread: The DRM code is not for DRM, it's for authentication so they can control the quality of the end product. It certifies that the resulting file has had the correct MQA filters applied and has been approved by the label/producer/artist or some subset thereof. I don't know if this answers your questions. It would appear to have the ability to prevent playback as undecoded MQA with the MQA light on. Some people have shown the light stays on when it should not in some cases anyway. It would appear to have the potential for abuse in the more common manner of DRM in the future. Of course MQA people are saying it has never been done and they aren't going to do that. tmtomh 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
Popular Post Fokus Posted October 11, 2018 Popular Post Share Posted October 11, 2018 There are two aspects. The first is the 'hard' DRM, a mechanism observed in the code that allows for some audio bits to be swapped, resulting in recognisable but distorted replay unless the user can show the proper key. AFAIK this is not used today, but it is in there nevertheless. The second is conceptual DRM. The user can never have access to the fully unfolded audio in the digital domain. That means no inspection, and no compatibility with presently-installed (*) digital domain signal processing. These are two significant restrictions compared to open formats, hence 'managing my rights'. (* Of course MQA invite us to ditch it all and purchase new, MQA-approved processors.) wgscott, Northern_Canuck, MrMoM and 4 others 3 4 Link to comment
Popular Post bambadoo Posted October 11, 2018 Popular Post Share Posted October 11, 2018 http://archimago.blogspot.com/2018/04/musings-on-drm-mqa-supposed-techno.html Some thoughts there. Hugo9000, wgscott and MrMoM 2 1 Link to comment
Popular Post mansr Posted October 11, 2018 Popular Post Share Posted October 11, 2018 The full content of an MQA file cannot be accessed without a licensed decoder. That alone makes it a form of DRM. That the files can be copied in their encoded form is irrelevant. This is true of every software based DRM scheme. Even a DVD can be replicated without decrypting the protected parts. What matters is how the data can be usefully accessed. In the more draconian DRM systems, the decoder contacts a remote server which verifies that the user holds a valid licence and only then supplies the decryption key. The server often imposes severe restrictions such as a limited number of playbacks. If the server becomes inaccessible, possibly permanently, the protected file is rendered useless. MQA is not quite that bad. As it does not "phone home," there can be no per-play checks. Remember, the same is true for DVDs, and everybody agrees that they have DRM. The MQA defenders now point out that their files allow partial playback even without a decoder. This is, however, not the entire truth. Firstly, such playback does not reach even CD quality. Secondly, while reverse engineering the decoder, I found a mechanism that allows the entire file to be encrypted, making it completely unplayable on non-MQA systems. While it is true that no files using this mode have yet been found in the wild, this does not in any way mean there never will. After all, why would the feature be included if there was no intent to use it? There is every reason to believe that if MQA support were to become sufficiently widespread, at least some music would start being distributed with this encryption enabled. If you bought such a file, it would become totally unplayable the day MQA equipment is no longer available, and this day will come. Nothing lasts forever. Sonicularity, opus101, Fokus and 16 others 14 3 2 Link to comment
sphinxsix Posted October 11, 2018 Share Posted October 11, 2018 6 hours ago, mansr said: The MQA defenders now point out that their files allow partial playback even without a decoder. This is, however, not the entire truth. Firstly, such playback does not reach even CD quality. True. My listening test impressions: A great thread idea! I was asking myself the same question. Link to comment
Popular Post Samuel T Cogley Posted October 11, 2018 Popular Post Share Posted October 11, 2018 18 hours ago, trappy said: I have noticed that the MQA versions of some of the most obviously watermarked recordings (i.e older DG) do not exhibit watermarking signatures. Especially obvious when both versions are there. I’ll try to find an example later. I’m thinking the Chicago Abbado Mahler 5... I have noticed this as well. The only favorable thing I can say about MQA. The MQA'd versions sound much better than the watermarked versions. Not because of MQA, but because of the absence of the atrocious watermarking. trappy, tmtomh and MikeyFresh 2 1 Link to comment
Popular Post Miska Posted October 11, 2018 Popular Post Share Posted October 11, 2018 7 hours ago, mansr said: The MQA defenders now point out that their files allow partial playback even without a decoder. This is, however, not the entire truth. Firstly, such playback does not reach even CD quality. And that is in many ways similar to the SACD. One could play the RedBook resolution on standard unprotected player, or rip to a computer. But the play the DSD layer, one would need to have licensed hardware. And DSD data could only be sent over protected link to another protected and licensed piece of hardware. Only analog outputs were allowed at full resolution. Digital output over S/PDIF or similar was allowed to be only RedBook quality. And SACD's protections lasted longer than DVD's... MQA is just worse in this respect by not allowing even RedBook quality without licensed and approved decoder. MikeyFresh and Shadders 1 1 Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
mansr Posted October 11, 2018 Share Posted October 11, 2018 1 minute ago, Miska said: And that is in many ways similar to the SACD. One could play the RedBook resolution on standard unprotected player, or rip to a computer. But the play the DSD layer, one would need to have licensed hardware. And DSD data could only be sent over protected link to another protected and licensed piece of hardware. Only analog outputs were allowed at full resolution. Digital output over S/PDIF or similar was allowed to be only RedBook quality. Slight correction: the PS3 outputs SACD as 88.2/24 over Toslink. Link to comment
Popular Post tmtomh Posted October 11, 2018 Popular Post Share Posted October 11, 2018 44 minutes ago, Miska said: And that is in many ways similar to the SACD. One could play the RedBook resolution on standard unprotected player, or rip to a computer. But the play the DSD layer, one would need to have licensed hardware. And DSD data could only be sent over protected link to another protected and licensed piece of hardware. Only analog outputs were allowed at full resolution. Digital output over S/PDIF or similar was allowed to be only RedBook quality. And SACD's protections lasted longer than DVD's... MQA is just worse in this respect by not allowing even RedBook quality without licensed and approved decoder. Absolutely yes - and, neither Sony nor anyone else ever tried to claim SACD was not a DRM'd format. And they certainly didn't send people to publicly impugn the integrity who pointed out that the format was DRM'd either. Hugo9000, Ralf11 and MikeyFresh 2 1 Link to comment
Miska Posted October 11, 2018 Share Posted October 11, 2018 41 minutes ago, mansr said: Slight correction: the PS3 outputs SACD as 88.2/24 over Toslink. Ahh, that's something I didn't know! That is quite sensible. All the other SACD players I've seen only output 44.1/16 when playing SACD... Even the 5.1 channel Sony I still have... Which is actually a curious device because of it's Sony DSD processor. It did speaker distance and level adjustments when playing DSD. I even checked the PCB, and for all other channels except front stereo the DAC chip PCM pins are not even connected, so it certainly did that with DSD playback... (it uses Burr-Brown DAC chips) Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
Popular Post Ralf11 Posted October 11, 2018 Popular Post Share Posted October 11, 2018 54 minutes ago, Miska said: ... MQA is just worse in this respect by not allowing even RedBook quality without licensed and approved decoder. MP3QA Hugo9000 and crenca 2 Link to comment
mansr Posted October 11, 2018 Share Posted October 11, 2018 43 minutes ago, Miska said: Ahh, that's something I didn't know! That is quite sensible. All the other SACD players I've seen only output 44.1/16 when playing SACD... Even the 5.1 channel Sony I still have... Which is actually a curious device because of it's Sony DSD processor. It did speaker distance and level adjustments when playing DSD. I even checked the PCB, and for all other channels except front stereo the DAC chip PCM pins are not even connected, so it certainly did that with DSD playback... (it uses Burr-Brown DAC chips) Filter bypass mode on BB chips uses the DSD pins for PCM input. Link to comment
Miska Posted October 11, 2018 Share Posted October 11, 2018 35 minutes ago, mansr said: Filter bypass mode on BB chips uses the DSD pins for PCM input. I'm not sure if the DSD1751 even has such... But I think I checked this loong time ago. Closest datasheet I am now able to find is for DSD1702: http://www.ti.com/lit/ds/symlink/dsd1702.pdf I'm pretty sure it has remodulator for DSD. They had also PCM to DSD upsampling quite a while ago in their players. Not so different from the good old CS4328 DAC chip. I still have one DAC I built with that chip when it was new. CS4328 datasheet describes: Quote The architecture includes an 8× oversampling fil- ter followed by a 64× oversampled one-bit delta-sigma modulator. The output from the one bit modulator controls the polarity of a reference voltage which is then passed through an ultra- linear analog low-pass filter. The result is line-level outputs with no need for further filter- ing. Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
Fokus Posted October 12, 2018 Share Posted October 12, 2018 8 hours ago, tmtomh said: And they certainly didn't send people to publicly impugn the integrity who pointed out that the format was DRM'd either. When I published a critical comment on SACD on my website my provider and I got a cease and desist from Sony legal. Link to comment
mansr Posted October 12, 2018 Share Posted October 12, 2018 11 hours ago, Miska said: I'm not sure if the DSD1751 even has such... But I think I checked this loong time ago. Closest datasheet I am now able to find is for DSD1702: http://www.ti.com/lit/ds/symlink/dsd1702.pdf I'm pretty sure it has remodulator for DSD. It's easy enough to check what's being sent to the chips using a scope or logic analyser. 11 hours ago, Miska said: They had also PCM to DSD upsampling quite a while ago in their players. Not so different from the good old CS4328 DAC chip. I still have one DAC I built with that chip when it was new. CS4328 datasheet describes: Quote The architecture includes an 8× oversampling fil- ter followed by a 64× oversampled one-bit delta-sigma modulator. The output from the one bit modulator controls the polarity of a reference voltage which is then passed through an ultra- linear analog low-pass filter. The result is line-level outputs with no need for further filter- ing. That sounds like a description of just about any sigma-delta DAC chip. Link to comment
Miska Posted October 12, 2018 Share Posted October 12, 2018 This is getting "slightly" off-topic... 2 hours ago, mansr said: It's easy enough to check what's being sent to the chips using a scope or logic analyser. I believe I checked with spectrum analyzer when the device was new. Now I tried to check again and the player doesn't recognize DSD layers anymore, thinks those are only CD. Too long in storage or something and the pickup head is dead. Tried cleaning up the lens, etc. That leaves me only with one functional SACD player left - a stereo-only Pioneer one. And I don't know if anybody is selling multi-channel non-PCM converting SACD players anymore now that Oppo also quit that stuff. Lovely part of DRM'ed content, similar thing happened with my HD-DVD discs. Luckily I have some of the SACD's ripped, not so lucky with HD-DVD. Sony also has a PCI card for doing similar plus more advanced DSD-to-DSD processing that is part of the Sonoma recording system: http://www.superaudiocenter.com/Products.htm They have their own ASIC they use in the SACD players, etc. 2 hours ago, mansr said: That sounds like a description of just about any sigma-delta DAC chip. Yeah, except this is one of the good old true 2.8 MHz 1-bit thingies. In the output, there's no rise in the noise floor, so the analog filter is nicely designed to match the modulator. There's only small noise bump around 2.8 MHz and notch plus peak in the middle where the 2.8 MHz frequency is. Nowadays I would put some extra analog filter there, as the 2.8 MHz frequency spike is at just around -50 dB. And the performance is quite nice overall. tmtomh 1 Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
Hugo9000 Posted October 12, 2018 Share Posted October 12, 2018 11 hours ago, Fokus said: When I published a critical comment on SACD on my website my provider and I got a cease and desist from Sony legal. Was it related to a potential or alleged violation of the Digital Millenium Copyright Act? 请教别人一次是5分钟的傻子,从不请教别人是一辈子的傻子 Link to comment
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