(2017-01-21, 21:20)arneson Wrote: [ -> ] (2017-01-21, 17:15)Steve100 Wrote: [ -> ]...
Decoding in Kodi
I would imagine that in time (may be a lot f time) the Kodi built-in player (PAPlayer) will include a decoder but decoding of this format is currently not generally available and can only be found in a limited amount of software and hardware. probably due to how new MQA still is.
Software Decoding
I am currently enquiring with MQA to obtain a list of all software-based decoders (media players with add-ons for decoding MQA) so that I can configure Kodi to use an external player instead of the internal PAPlayer for all FLAC files in the hopes that I can create seamless unfolding/Decoding of MQA while using Arneson's TIDAL2 Add-on. The output of PCM bit stream would be expanded/unfolded to 96/24 etc. (at least one unfold, maybe eventually more) from Source/Kodi without the need for hardware intervention.
Hello Steve,
I found MQA Decoding Explained on audiostream.com and MQA: Questions and Answers on stereophile.com which explain details of the MQA Codec.
If I understand it right, MQA is an Analog-to-Analog reproduction Codec. So the DAC Hardware has to decode the MQA informations to re-create exactly the same Analog Signal as it was Mastered in the Studio. And it can "Authenticate" that it is decodec correctly.
Because every DAC has a different analog signal characteristic to create the Line Output Signal (analog amplifier at the end) the DAC hast to apply device specific filters to the digital values to reproduce the correct audio signal at the end of the amplifier.
I Think, that is the reason that software decoding to 96/24 or 192/24 can only be a kind of "controlled upsampling" and never can reproduce the audio signal to 100%.
So 48/24 or 44.1/24 is the best quality we can get with software decoding in Kodi.
And the most important thing: You have perfect ears to hear any difference between 48/24 and 96/24 or 192/24 !!
(My ears are too bad to detect any difference )
Please correct me if I'm wrong !
arneson
Hi Arneson
Sorry for the delayed response. I too read through a lot of the content from the author of MQA including his video:
http://www.mqa.co.uk/customer/how-it-works and I must admit that there is still much I do not understand. Some of the math and Science involved is very complex and the explanation raises more questions than it answers.
What I believe we can draw from use of this format with TIDAL is this; As you are aware MQA is based on multiple folds A,B & C (encapsulation) and what I can confirm is that at least the first fold (probably not all folds) can be digitally decoded. I believe, although I am guessing here that this is a digital-to-digital process as it is decoded within the digital realm.
When we use software-based decoders such as TIDAL's built-in decoder (when MQA pass-through is not selected) we see the following. I should point out that I am able to see TIDAL's output PCM spec as my AV Receiver, like many, has the capability to display current stream bit-depth and sample rate through any input HDMI, in this instance from my HTPC using TIDAL or KODI.
- When playing a standard 'HiFi' stream the PCM signal being received is 16-bit 44.1khz (CD Quality) as expected.
- When playing a 'Master' stream with MQA pass-through enabled it is being received as 24-bit 44.1khz or 48khz. Obviously, this is because my AV Receiver is not MQA capable.
When playing a 'Master' stream with MQA pass-through not enabled (internal MQA software decoding used) it is being received as 24-bit 88.2khz or 96khz.
So, I think it is safe to assume that at least the first fold can be unfolded digitally. But, I agree with you that I have also seen mention on numerous occasions the need to have each piece of hardware certified and balanced due to it's own unique characteristic of how analogue sound is handled through its own DAC. I think we can draw from this that the second unfold may be a separate analogue-to-analogue process that takes us up to the top end of 176.4Khz/192Khz (where available) like your Meridian Explorer 2 is capable of performing.
As we know, TIDAL at least can only perform the first unfold. This could be an imposed restriction or perhaps because the last unfold cannot be performed in the digital realm. All I know is that we will find out eventually as MQA becomes more mainstream.
In my own humble opinion, although nice to have (more for piece of mind's sake that I am not losing out on something) I am not that overly bothered about not having the second unfold up to 176.4Khz/192Khz. Either having a 16-bit to 24-bit increase or a doubling in sample rate is a somewhat large improvement over the standard CD quality. The fact that the software decoding does both is more than enough for me. Personally I cannot hear any further improvement beyond 24-Bit 96Khz. It sounds amazing anyway.
Steve