Roon & MQA - Software Decoding Is Coming!

[miguelito]

I dunno, something along the lines of a more readily editable SDM format at the recording end?

The problem with 1-bit SDM is that it spreads magnitude to the time domain, so it's hard to edit (obviously you know all this). The only way around this that I know is what some editing consoles do which is subdivide that 1-bit into 8-bits (sort of creating an 8-bit PCM sample off of every SDM bit). I can't imagine any other way to adjust amplitude in real time. Obviously all of you know this....

[mansr]

Thanks for the explanation.

 

The question about editability is due to the fact that the native output of virtually all studio recording setups in use is SDM, requiring conversion to a PCM format for editing. Since the move to SDM came at least in part due to its lower cost, I don't think we're going to see a switch back to studio recording equipment with PCM as a native format. I was just hoping for a format that would allow studios to use either current equipment or make changes at relatively low cost and still allow editing, without the necessity for lossy conversion between SDM and PCM that is done to enable editing today (though I understand, perhaps incorrectly, that workstations permitting more editing operations in SDM format than are available today are supposed to be on their way).

 

SDM is used at the digital/analogue interfaces since it provides superior performance to realisable R-2R D/A or flash A/D converters. That's all there is to it.

[Miska]

The problem with 1-bit SDM is that it spreads magnitude to the time domain

 

It is no different from any other number of SDM bits... Same relative difficulty regardless of number of bits.

[Miska]

I was just hoping for a format that would allow studios to use either current equipment or make changes at relatively low cost and still allow editing, without the necessity for lossy conversion between SDM and PCM that is done to enable editing today (though I understand, perhaps incorrectly, that workstations permitting more editing operations in SDM format than are available today are supposed to be on their way).

 

Main restricting factor is probably that most studios use something like 96/24 PCM as their recording and storage format. The market for anything else is so much smaller and DAW manufacturers are so busy with the existing larger market feature requests, that they don't have interest nor time to put lot of effort to something they see as a niche market. And fundamentally, from internal software architecture point of view, many existing DAW's probably just cannot operate with anything else than low rate PCM in sensible way. For example HQPlayer has two separate "DSP engines" inside, one for PCM and one for SDM. Doing and maintaining the same for a DAW product is quite significant effort they are not going to start easily. But eventually someone will get on it and have competitive advantage for a while...

 

Sonoma can do quite a lot with DSD, but I think it's still limited to DSD64. Pyramix can do some basic editing too.

[austinpop]

This thread has gone silent. Anybody have info on when (or even if) Roon MQA SW decoding is coming?

 

I'm into my trial period, and this is one of the potential features that will tip the scales.

[jhwalker]

This thread has gone silent. Anybody have info on when (or even if) Roon MQA SW decoding is coming?

 

I'm into my trial period, and this is one of the potential features that will tip the scales.

 

They have stated it is coming, but have given no timeline.

 

FWIW, a couple weeks back, they stated they were waiting on some info / code from MQA to address their unique needs as a client / server system (presumably, code to run at the server end to do the "unfolding" prior to their new DSP pipeline).

[miguelito]

They have stated it is coming, but have given no timeline.

 

FWIW, a couple weeks back, they stated they were waiting on some info / code from MQA to address their unique needs as a client / server system (presumably, code to run at the server end to do the "unfolding" prior to their new DSP pipeline).

Audirvana's MQA decoding is already out - and works great. If I had to guess, it's the DSP part that is contentious. If MQA has objections in this regard I surmise it will be a long time before we see anything...

[jhwalker]

Audirvana's MQA decoding is already out - and works great. If I had to guess, it's the DSP part that is contentious. If MQA has objections in this regard I surmise it will be a long time before we see anything...

 

Why would they have an issue with Roon's DSP if Audirvana's is allowed? i.e., Audirvana allows you to run AUs, resample with filters, etc., against the unfolded content - seems MQAs DSP is just more of the same.

[miguelito]

Why would they have an issue with Roon's DSP if Audirvana's is allowed? i.e., Audirvana allows you to run AUs, resample with filters, etc., against the unfolded content - seems MQAs DSP is just more of the same.

Ok, it was not clear to me you could do this in A+3 - I played with it some but did not get to the point of trying to use AUs or iZotope resampling.

 

My speculation comes from the fact that the binaries to do the first unfold have been available for a long time and implemented in both TIDAL and A+3. So I cannot imagine the hangup is on this side. Plus MQA has had reticense to allow any post processing in the past. It's just my speculation given I see no technical hurdles.

[jhwalker]

Ok, it was not clear to me you could do this in A+3 - I played with it some but did not get to the point of trying to use AUs or iZotope resampling.

 

My speculation comes from the fact that the binaries to do the first unfold have been available for a long time and implemented in both TIDAL and A+3. So I cannot imagine the hangup is on this side. Plus MQA has had reticense to allow any post processing in the past. It's just my speculation given I see no technical hurdles.

You may be right - I just jumped to the assumption that it had something to do with the Roon architecture (e.g., server + endpoints) rather than any reticence about processing, since we can see they've allowed that (e.g., software decoding + additional processing) in Audirvana.

[miguelito]

You may be right - I just jumped to the assumption that it had something to do with the Roon architecture (e.g., server + endpoints) rather than any reticence about processing, since we can see they've allowed that (e.g., software decoding + additional processing) in Audirvana.

In Roon, all DSP is done in the core - according to Roon's devs, I asked on their forum a while back. MQA unfolding will also be done in the core, I don't think it's any different from other DSP steps. I would expect that an endpoint will tell the core that the DAC can/cannot decode MQA in a similar way it communicates the max sample rate for upsampling.

[bobbmd]

@austinpop/jhwalker/miguelito: as of yesterday I noticed if you go to TIDALS options on top of the page on ROON under 'what's new' there is now a MASTERS box and all MQA(not exactly all)that TIDAL offers come up. Prior to this like last week or more whenever I played an MQA playlist that I made on TIDAL through ROON I got the blue light alone or the blue light and 1-2 white lights on my ME2 so I assume ROON has been'unfolding' or passing through MQA albums for some time now. But only at 24/44.1 whereas A+3 bits are 24/44 24/96 24/192 or with 2L recordings 352. Am I interrupting this correctly??

[jhwalker]

@austinpop/jhwalker/miguelito: as yesterday day if you go to TIDALS options on top of the page on ROON under 'what's new' there is now a MASTERS box and all MQA(not exactly all)that TIDAL offers come up. Prior to this like last week or more whenever I played an MQA playlist that I made on TIDAL through ROON I got the blue light alone or the blue light and 1-2 white lights on my ME2 so I assume ROON has been'unfolding' or passing through MQA albums for some time now. But only at 24/44.1 whereas A+3 bits are 24/44 24/96 24/192 or with 2L recordings 352. Am I interrupting this correctly??

 

Roon will pass through Tidal Masters / MQA to MQA-enabled DACs if you turn off all other processing so that the stream is bit-perfect. In this case, the MQA-enabled DAC will playback the music at whatever resolution it was originally encoded in.

 

It will not (yet) do the software decoding that is necessary for non MQA-enabled DACs properly to play MQA tracks in 24/88 or 24/96 resolution.

 

 

Sent from my iPhone using Computer Audiophile

[austinpop]

Thanks guys, let me add a couple of my observations too.

 

1. I just noticed on the Tidal app on Windows (so presumably on Mac too), that all Masters albums now have an M logo on the album thumbnail. That is great news, if you can now identify MQA albums in search results.
   
2. I have some MQA files in my library (2L samples). Roon seems to not only recognize them after analysis, but also the native original resolution. In the album view, it shows MQA on the thumbnail, and then when you click through, it shows something like "FLAC 44.1kHz, 24bit, MQA 352.8kHz"
   

So it seems like things are moving.

[miguelito]

@austinpop/jhwalker/miguelito: as of yesterday I noticed if you go to TIDALS options on top of the page on ROON under 'what's new' there is now a MASTERS box and all MQA(not exactly all)that TIDAL offers come up. Prior to this like last week or more whenever I played an MQA playlist that I made on TIDAL through ROON I got the blue light alone or the blue light and 1-2 white lights on my ME2 so I assume ROON has been'unfolding' or passing through MQA albums for some time now. But only at 24/44.1 whereas A+3 bits are 24/44 24/96 24/192 or with 2L recordings 352. Am I interrupting this correctly??

Assuming you turn DSP off, Roon should have always passed through the untouched data for your ME2 DAC to properly decode MQA. I am guessing what you're seeing is just a resync of the TIDAL data (which I don't think happens instantly).

[arglebargle]

On 2017-01-06 at 2:38 AM, Miska said:

 

Whenever MQA content is detected (indicated in the GUI), there's special algorithm used to strip most of the MQA noise from LSBs. Then the poly-sinc-mqa/poly-sinc-mqa-mp filters are tuned to fit the MQA content. Those same filters are also suitable for upsampling hires (88.2k sampling rate or higher) content. Those filters have gentler roll-off, but not as much as "minringFIR", so it they are somewhere between poly-sinc-short and minringFIR. Also roll-off shape and stop-band behavior is different between the three, so the filters are sort of completely different.

 

So now the noise-bit-stripping and filters are separate. This is sort of "make most out of content and try to do it sort of the way it was intended".

 

Note that when you play MQA content from Roon, there is no indication of the track content type and thus the bit stripping is never active. It only works when HQPlayer has direct access to the source content. You can of course still use the poly-sinc-mqa* filters.

 

Ressurecting this old thread because I am listening to some MQA titles through Roon/HQP using poly-sinc-mqa-mp for the first time. Sounds wonderful. Does the fact that Roon now identifies Tidal MQA streams in signal path mean bit stripping could be applied to streams from Roon?

 

I haven't really followed the mqa stuff but withmore and more titles appearing, and an unknown amount of time before Roon does the unfolding, I'm just experimenting to see how good things can sound with what hardware/software I have. Answer: Pretty damn good. 

[Miska]

3 hours ago, arglebargle said:

 

Ressurecting this old thread because I am listening to some MQA titles through Roon/HQP using poly-sinc-mqa-mp for the first time. Sounds wonderful. Does the fact that Roon now identifies Tidal MQA streams in signal path mean bit stripping could be applied to streams from Roon?

 

I haven't really followed the mqa stuff but withmore and more titles appearing, and an unknown amount of time before Roon does the unfolding, I'm just experimenting to see how good things can sound with what hardware/software I have. Answer: Pretty damn good. 

 

Roon doesn't pass that info over to HQPlayer. But I could still detect the MQA content, but not sure if it is really worth it.

 

[arglebargle]

Makes sense. I'm curious to see what they do with unfolding eventually but it's just not that big a factor in my listening as is.  Cheers! 

[firedog]

Roon 1,5 now being released with sophisticated MQA implementation, including DSP

https://community.roonlabs.com/t/roon-1-5-is-now-live/42309
https://darko.audio/2018/05/roon-1-5-adds-mqa-linn-ds-support/

[Miska]

Works with HQPlayer too, so you have lot of options for upsampling filters instead of the MQA set.

 

[asdf1000]

15 minutes ago, Miska said:

Works with HQPlayer too, so you have lot of options for upsampling filters instead of the MQA set.

 

 

When using Roon+HQP, the MQA signal doesn't 'carry through' to an MQA DAC does it? The way Roon DSP does now with v1.5? So that the MQA DAC shows it's MQA indicator.

 

I'm guessing there's no chance of that ever happening?

[Solstice380]

2 hours ago, Em2016 said:

I'm guessing there's no chance of that ever happening?

 

I’m not @Miska but you are probably correct. 

[mav52]

This new 1.5 version of ROON now does DSP for MQA.

" We have also covered some new ground with MQA: Roon will not only be able to perform DSP on unfolded MQA content, it will do so without destroying the MQA Signalling information–meaning: it is now possible to use features like EQ, Room Correction, and Volume Leveling while still taking advantage of the rendering capabilities of your MQA DAC. "

 

https://community.roonlabs.com/t/roon-1-5-is-now-live/42309?u=wklie

[firedog]

2 minutes ago, mav52 said:

This new 1.5 version of ROON now does DSP for MQA.

" We have also covered some new ground with MQA: Roon will not only be able to perform DSP on unfolded MQA content, it will do so without destroying the MQA Signalling information–meaning: it is now possible to use features like EQ, Room Correction, and Volume Leveling while still taking advantage of the rendering capabilities of your MQA DAC. "

 

https://community.roonlabs.com/t/roon-1-5-is-now-live/42309?u=wklie

I've been playing with the new version. It has one really outstanding feature: you can playback MQA files through Roon (no need for the Tidal desktop app) and it adds the MQA tag to all the MQA albums that Tidal provides. Makes it easy to identify them in order to add them to the library... or to ignore them. Also makes it easy to setup a comparison listening test.

[firedog]

delete post. false alarm