Are we heading for a time when all CDs will be MQA coded - no redbook available?

[mansr]

Was the firmware reverse engineered or is it an external dependency for the tools?

The mqadec and mqarender tools use the decoder library from the Bluesound firmware. The scan tools are based on reverse engineered information.

 

[Mnyb]

So did you run her latest album through @mansr 's checker to see if it's MQA free?

Nope I no longer have a Linux desktop from where i could compile the application.

 

[nimar]

Nope I no longer have a Linux desktop from where i could compile the application.

It builds on osx, need Xcode, libsndfile and to comment out the `--as-needed` linker flag from the makefile.

-LDFLAGS += -Wl,--as-needed
+LDFLAGS += -Wl#,--as-needed

 

[Jimbob54]

Here is a thought. What if Spotify HIFI or whatever it is called is actually 13 bit CD - lite MQA?

I for one welcome the New Order.

 

[voodooless]

Here is a thought. What if Spotify HIFI or whatever it is called is actually 13 bit CD - lite MQA?

Why think that?

 

[mansr]

The mqadec and mqarender tools use the decoder library from the Bluesound firmware. The scan tools are based on reverse engineered information.

Speaking of Bluesound, I finally got round to updating those tools to work with the latest BluOS firmware. I also added a little script that extracts the required file from the firmware image, even downloading it for you (bypassing the promise not to be naughty). I may not be allowed to distribute that file, but nothing says I can't make it easy for others to obtain.

 

[Jimbob54]

Why think that?

Just a thought. Don't get me wrong, I'm not saying it will be hidden. But they have taken a dogs age to make the easy move to CD quality.

And all of a sudden the industry introduces this slimmed down mqa on a CD thingy.

Pure coincidences. Much suspicious minds.

 

[voodooless]

Just a thought. Don't get me wrong, I'm not saying it will be hidden. But they have taken a dogs age to make the easy move to CD quality.

I'd hardly call it easy. There are millions of devices with Spotify Connect that likely will not be compatible with whatever lossless codec they would want to use. That is quite a hurdle that needs to be taken care of.

Regarding what I asked at #161:

What happens to the original noise shaping and dithering? Are they still encoded in the 3 MQA bits somehow? Or is that just lost information?

The original patent sheds some light on this:

So at least it looks like the lower bits do contain some noise shaping and dithering after all. But this is for the 24-bit version, the 16-bit version must only contain parts of this since there are only 3 bits left to wiggle with. All of this noise shaping significantly lowers the actual information density of the lower bits. There really is not a lot of room left.

Als what I really don't understand: Many of these tests have shown that the HF part is simply a lower volume mirror copy of the LF part. If so, why do we need to compress anything? For creating this mirror image I don't need any bits, just some DSP. So what gives?

 

[danadam]

Als what I really don't understand: Many of these tests have shown that the HF part is simply a lower volume mirror copy of the LF part.

The LF and HF in this diagram are 0-24 kHz and 24-48 kHz bands, respectively. Unless I'm mistaken, the mirror copy you are talking about is of 0-48 kHz band into 48-96 kHz band. It happens after core decoding, in the rendering process, when 96 kHz sampling rate is upsampled to 192 kHz sampling rate.

 

[voodooless]

The LF and HF in this diagram are 0-24 kHz and 24-48 kHz bands, respectively. Unless I'm mistaken, the mirror copy you are talking about is of 0-48 kHz band into 48-96 kHz band. It happens after core decoding, in the rendering process, when 96 kHz sampling rate is upsampled to 192 kHz sampling rate.

Not according to this picture:

And folded back using an image editor:

 

[Jimbob54]

I'd hardly call it easy. There are millions of devices with Spotify Connect that likely will not be compatible with whatever lossless codec they would want to use. That is quite a hurdle that needs to be taken care of.

/QUOTE]

Can Apple devices still not play back FLAC btw? What do Tidal/ Qobuz do, transcode? Been a while since I used an i device

 

[voodooless]

Can Apple devices still not play back FLAC btw? What do Tidal/ Qobuz do, transcode? Been a while since I used an i device

That is quite irrelevant what the OS can play. Any software can just implement a decoder to PCM.

 

[Jimbob54]

That is quite irrelevant what the OS can play. Any software can just implement a decoder to PCM.

So what devices wont be able to play whatever lossless codec they decide to use? (per your post- the hurdle)

 

[danadam]

Not according to this picture:

The article says that it is like that for content with source sampling rate of 44.1/48 kHz. In such case, yes, it doesn't make sense (assuming that hires has any sense in the first place). I suspect there won't be mirroring at this frequency for content with legit higher sampling rate.

I guess they have a product that expects 88.2/96 kHz on input and that's one way of creating such input

 

[voodooless]

So what devices wont be able to play whatever lossless codec they decide to use? (per your post- the hurdle)

It's not the device capabilities that are the problem here, but the standardization of Spotify Connect. I don't know the ins and outs, but if they have not foreseen to send anything other than Vorbis, they basically need to amend the standard and wait for all device manufacturers to update the firmware/app to comply with the new stuff. As long as it's only apps, that is not an issue, but there are also tonnes of hardware devices out there.

 

[buz]

Don't know, I don't know anyone that uses lossy files in my presence. People that I know use vinyl, cassette, CD, DVD, Blu Ray, 4K or 8K. .

All digital video you are likely to ever encounter (outside high end studios) uses lossy audio compression. Not generally MP3 though (I think MPEG1 on VCD did).

 

[mansr]

The original patent sheds some light on this:

So at least it looks like the lower bits do contain some noise shaping and dithering after all. But this is for the 24-bit version, the 16-bit version must only contain parts of this since there are only 3 bits left to wiggle with. All of this noise shaping significantly lowers the actual information density of the lower bits. There really is not a lot of room left.

That figure doesn't match the bit layout actually used in MQA files.

 

[voodooless]

That figure doesn't match the bit layout actually used in MQA files.

Do you have a matching picture for 16 and 24-bit content?

 

[Jimbob54]

It's not the device capabilities that are the problem here, but the standardization of Spotify Connect. I don't know the ins and outs, but if they have not foreseen to send anything other than Vorbis, they basically need to amend the standard and wait for all device manufacturers to update the firmware/app to comply with the new stuff. As long as it's only apps, that is not an issue, but there are also tonnes of hardware devices out there.

Ah, got you- We await what they come out with then- the press anouncement was suitably vague as to the actual format/ codec. But given they are saying lossless, probably not some form of MQA then- I withdraw my idle speculation.

"Spotify HiFi will deliver music in CD-quality, lossless audio format to your device and Spotify Connect-enabled speakers, which means fans will be able to experience more depth and clarity while enjoying their favorite tracks."

 

[mansr]

All digital video you are likely to ever encounter (outside high end studios) uses lossy audio compression. Not generally MP3 though (I think MPEG1 on VCD did).

Bluray audio is lossless (PCM, DTS-MA, or Dolby TrueHD) more often than not. Lossless audio on DVD is possible but rarely used.