Hiro Posted September 10, 2015 Share Posted September 10, 2015 streaming hd content using cd-like bandwith requirements? don't know if that is real... Aren't current CDQ streaming services using compression as well, albeit lossless? It appears to me that what MQA is doing is trading a few extra bits of compression for its lossless status. Link to comment
MikeJazz Posted September 10, 2015 Share Posted September 10, 2015 Aren't current CDQ streaming services using compression as well, albeit lossless? It appears to me that what MQA is doing is trading a few extra bits of compression for its lossless status. I am not following you but what I know... So, for example, Tidal is compressing when streaming from there...So what exactly is the "decompressing" mechanism on the receiving side? http://www.computeraudiophile.com/members/mikejazz/ funded this campain: http://igg.me/at/geekpulseaudio/x/5216671 Link to comment
Miska Posted September 10, 2015 Share Posted September 10, 2015 streaming hd content using cd-like bandwith requirements? don't know if that is real... If it is lossless, then FLAC will probably perform at least as well and doesn't involve $$$ licensing costs to Meridian. Bandwidth with FLAC streaming is not an issue, nor streaming even uncompressed DSD128. Peanuts compared to Netflix or YouTube streaming 1080p or 4k video... Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
Jud Posted September 10, 2015 Share Posted September 10, 2015 As I read tailspn correctly, what is needed is recording interfaces which will output the SDM, which can then be edited without conversion. There would only need to be a conversion at the Mastering stage to the chosen DSD or PCM... If DSD is chosen, I believe that *is* the edited SDM output and no conversion is needed for the master. So to that extent (at least if my belief is correct) what happens inside the box matters. One never knows, do one? - Fats Waller The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein Computer, Audirvana -> optical to EtherREGEN -> microRendu -> ISO Regen -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature. Link to comment
Miska Posted September 10, 2015 Share Posted September 10, 2015 So, for example, Tidal is compressing when streaming from there...So what exactly is the "decompressing" mechanism on the receiving side? Tidal uses standard FLAC over HTTP, so it can be technically played by any player that can play FLAC over HTTP. (HQPlayer for example can play all the supported file formats over HTTP, including DSD) Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
Nikhil Posted September 10, 2015 Author Share Posted September 10, 2015 Well, ta ta for now audiofans, I'm off to Budapest to join Jared and Hein Dekker for four day session of recording Ivan Fischer and The Budapest Festival Orchestra playing the Mahler 7. Jared will be using his customary Channel Classics analog mixing desk and Grimm AD1 converter recording at 64fs. I'm along to do a simultaneous 5 mic surround using the fabulous DPA 4041 microphones as an experiment, recording 256fs on a Merging Pyramix/Horus. The really exciting part though for headphone lovers is an additional binaural head DSD recorded at 256fs, and potentially be released! See ya soon! Tom Huge fan here of Ivan Fischer and the BFO! Love those recordings. Will look forward to when you are going to have those available for download. Custom Win10 Transport | Mutec MC-3+ Smart Clock USB | Lampizator Amber | Acoustic Portrait Thiyaga | ATC SCM20SL Link to comment
craighartley Posted September 10, 2015 Share Posted September 10, 2015 Well, ta ta for now audiofans, I'm off to Budapest to join Jared and Hein Dekker for four day session of recording Ivan Fischer and The Budapest Festival Orchestra playing the Mahler 7. Jared will be using his customary Channel Classics analog mixing desk and Grimm AD1 converter recording at 64fs. I'm along to do a simultaneous 5 mic surround using the fabulous DPA 4041 microphones as an experiment, recording 256fs on a Merging Pyramix/Horus. The really exciting part though for headphone lovers is an additional binaural head DSD recorded at 256fs, and potentially be released! See ya soon! Tom I'd love to (buy and) hear the 256 binaural; 256 stereo too for that matter! Craig Link to comment
mansr Posted September 10, 2015 Share Posted September 10, 2015 If it is lossless, then FLAC will probably perform at least as well and doesn't involve $$$ licensing costs to Meridian. MQA is not lossless. From what I can gather, the MQA encoding process works something like this: A 192/24 source is divided into three main frequency bands: 0-24 kHz, 24-48 kHz, and 48-96 kHz. The 0-24 kHz band is left untouched. The high bands are compressed with some lossy algorithm utilising the fact that typical musical content tends to roll off towards high frequencies. Above 48 kHz, there's typically only a few bits worth of dynamic range, so in the top band, the compression factor can be made very high. This compressed high-frequency content is encoded so as to resemble noise and stuffed into the low 6 or so bits of the 48/24 PCM data. With most ADCs and DACs achieving only 20-bit precision at best, those bits would be mostly noise anyhow, so this replacement isn't seen as causing any loss of fidelity. Finally, this 48/24 data is losslessly compressed using traditional means, e.g. FLAC. This is all based on what little information has been made publicly available, so I could of course be mistaken. Link to comment
bmoura Posted September 10, 2015 Share Posted September 10, 2015 If it is lossless, then FLAC will probably perform at least as well and doesn't involve $$$ licensing costs to Meridian. Bandwidth with FLAC streaming is not an issue, nor streaming even uncompressed DSD128. Peanuts compared to Netflix or YouTube streaming 1080p or 4k video... Interestingly, the Meridian MQA process talks of using techniques such as predistortion of the music during encoding and then later reversing that processing for listeners with MQA equipped software and hardware (DACs). Based on the MQA demo I've attended, I find music sounds better in FLAC and DSD formats then via MQA - even when decoded on some rather expensive Meridian gear. As always, at the end of the day each listener will need to listen to MQA - decoded and not - to see how well they believe it works. Link to comment
bmoura Posted September 10, 2015 Share Posted September 10, 2015 I still don't understand why someone would want to use MQA... Having heard MQA, I agree. Link to comment
bmoura Posted September 10, 2015 Share Posted September 10, 2015 Well, ta ta for now audiofans, I'm off to Budapest to join Jared and Hein Dekker for four day session of recording Ivan Fischer and The Budapest Festival Orchestra playing the Mahler 7. Jared will be using his customary Channel Classics analog mixing desk and Grimm AD1 converter recording at 64fs. I'm along to do a simultaneous 5 mic surround using the fabulous DPA 4041 microphones as an experiment, recording 256fs on a Merging Pyramix/Horus. The really exciting part though for headphone lovers is an additional binaural head DSD recorded at 256fs, and potentially be released! See ya soon! Tom Nice! Some of the Binaural DSD recordings on Native DSD are very convincing over headphones. My favorite Binaural DSD recording to date is Misa Criolla by Musica Temprana on the Cobra Records label. Definitely worth a download! https://cobra.nativedsd.com/albums/misa-criolla Link to comment
Tony Lauck Posted September 10, 2015 Share Posted September 10, 2015 Tony, with all respect, I'll take your post with a grain of salt. People have been using all kinds of DSD converters and were still taking advantage of lossless DST compression for SACD. I tried compressing movement one (2 channel) of the Fischer Mahler 9 made with the Grimm ADC using Winzip. The "old" compression method reduced the size by 30%, but the "best" compression method reduced the size by 50%. (By comparison, FLAC compression usually reduces the size by about 40%.) I didn't try DST compression, perhaps it would be much faster than WinZip, which was pathetically slow, although Winzip would still have been several times faster than real-time on my three year old core i5 machine. Link to comment
Miska Posted September 10, 2015 Share Posted September 10, 2015 A 192/24 source is divided into three main frequency bands: 0-24 kHz, 24-48 kHz, and 48-96 kHz. The 0-24 kHz band is left untouched. The high bands are compressed with some lossy algorithm utilising the fact that typical musical content tends to roll off towards high frequencies. Above 48 kHz, there's typically only a few bits worth of dynamic range, so in the top band, the compression factor can be made very high. This compressed high-frequency content is encoded so as to resemble noise and stuffed into the low 6 or so bits of the 48/24 PCM data. With most ADCs and DACs achieving only 20-bit precision at best, those bits would be mostly noise anyhow, so this replacement isn't seen as causing any loss of fidelity. Finally, this 48/24 data is losslessly compressed using traditional means, e.g. FLAC. This is also what I've understood about it. Let's say one would want to use 4 LSBs of 24 kHz band 24-bit data for the top octave (24-48 kHz), and that there's no more than about 6 bits worth of content there (which, BTW, is not the case for transients, so the mechanism would again worsen transient distortion already existing in 48 kHz sampled data). In any case if you then run the 6 bits for top octave through something like FLAC and embed that into 4 LSBs of the lower octave data and then again run that through FLAC again. This would be a two-pass encoding process making the content playable also at only 48 kHz capable gear. If you assume random noise in 4 LSBs in normal case, this could save some bandwidth because for the encoder the LSBs would look pretty much the same regardless if it is from first encoding pass or just random noise. But what I really doubt is if this is actually any better than just dithering the source content to 20-bit or something less based on predicted background noise level and encoding that using normal FLAC (since IIRC, FLAC can encode any number of bits up to 32). So the only advantage of this approach is to make it playable on equipment that supports only half of the max sampling rate. But this is hardly a useful feature these days... One could also run the top octave through CBR Vorbis/MP3/AAC to gain matching bitrate for the LSBs. Both are actually easy to experiment with, since it is simple two-pass encoding/decoding process. For saving bandwidth, it could be worth running dynamic range analysis/background noise estimation for the source content to determine how many bits to use for FLAC encoding. Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
MikeJazz Posted September 14, 2015 Share Posted September 14, 2015 Tidal uses standard FLAC over HTTP, so it can be technically played by any player that can play FLAC over HTTP. (HQPlayer for example can play all the supported file formats over HTTP, including DSD) OK, does this means is feasible to connect a NAA to a HQPlayer over HTTP? Is it complex? http://www.computeraudiophile.com/members/mikejazz/ funded this campain: http://igg.me/at/geekpulseaudio/x/5216671 Link to comment
Miska Posted September 14, 2015 Share Posted September 14, 2015 OK, does this means is feasible to connect a NAA to a HQPlayer over HTTP? Is it complex? NAA is completely unrelated, my comment is just about how HQPlayer itself can deal with source content. NAA comes to picture quite a bit later and from that point of view it doesn't matter where the content comes from. Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
徐中銳 Posted October 20, 2016 Share Posted October 20, 2016 Do readers know of ayre.com/insights_dsdvspcm.htm ? World’s First Valid Comparison of PCM versus DSD « an accurate picture Sono pessimista con l'intelligenza, ma ottimista per la volontà. severe loudspeaker alignment » Link to comment
Norton Posted October 20, 2016 Share Posted October 20, 2016 Do readers know of ayre.com/insights_dsdvspcm.htm ?World’s First Valid Comparison of PCM versus DSD As this doesn't even get through the first sentence without a reference to "Sony’s failed format of SACD", chances of an objective analysis are not good... Link to comment
esldude Posted October 20, 2016 Share Posted October 20, 2016 Already generated plenty of discussion here on CA once before. http://www.computeraudiophile.com/f8-general-forum/world%92s-first-valid-comparison-pulse-code-modulation-versus-direct-stream-digital-18636/ 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
徐中銳 Posted October 20, 2016 Share Posted October 20, 2016 Do you, or anyone, recognise the following photo to which, cropped, was a 90s album cover ? Already generated plenty of discussion here on CA once before. http://www.computeraudiophile.com/f8-general-forum/world%92s-first-valid-comparison-pulse-code-modulation-versus-direct-stream-digital-18636/ « an accurate picture Sono pessimista con l'intelligenza, ma ottimista per la volontà. severe loudspeaker alignment » Link to comment
esldude Posted October 21, 2016 Share Posted October 21, 2016 Do you' date=' or anyone, recognise the following photo to which, cropped, was a 90s album cover ?[/font'] Did not recognize it. Did google it and know what it is now. I'll refrain from naming it so others can comment. Not my cup of tea. 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
徐中銳 Posted October 21, 2016 Share Posted October 21, 2016 Pardon... It, the album, may well not be worth seeking out to Listen Without Prejudice... Did not recognize it. Did google it and know what it is now. I'll refrain from naming it so others can comment. Not my cup of tea. « an accurate picture Sono pessimista con l'intelligenza, ma ottimista per la volontà. severe loudspeaker alignment » Link to comment
esldude Posted October 21, 2016 Share Posted October 21, 2016 Pardon... It' date=' the album, may well not be worth seeking out to Listen Without Prejudice... Yes, I understood why you posted that. And the title more than the music was the point. My comment about it not being my cup of tea musically was related to the reason I did not recognize the album cover. So now that we're all clever the thread can continue. 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
徐中銳 Posted October 21, 2016 Share Posted October 21, 2016 The nature of the-Best [sic], things are just cyclical. And I remember... So now that we're all clever the thread can continue. Hansen's disdain for DSD have been long-standing. What should amaze us is DSD enthusiasts buying Ayre products that grudgingly allow DSD... As this doesn't even get through the first sentence without a reference to "Sony’s failed format of SACD", chances of an objective analysis are not good... Do readers know of ayre.com/insights_dsdvspcm.htm ?World’s First Valid Comparison of PCM versus DSD « an accurate picture Sono pessimista con l'intelligenza, ma ottimista per la volontà. severe loudspeaker alignment » Link to comment
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