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24/192 Music Downloads Are Very Silly Indeed (2012)

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Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#421

Post by massaman_yams »

ycombinete wrote: post #251
lz400 wrote: post #214

Earlier quoted context omitted.

As far as I know, people consistently fail to tell the difference in blind A/B tests in listening between (any decent) FLAC and a well ripped mp3 from the same source. I know I can't. I can't link to proper double blind studies but that's the general consensus in the non-BS-audiophile community as far as I know.

My anecdote is that I've done a number of these tests (Foobar has a plugin that allows you to do them on yourself), and I can reliably tell the difference between FLAC and 128 MP3, but can't tell the difference on 256 MP3 and up.

I only ever recall finding one track where I could hear differences in bass soundstage / positioning on 256+ mp3, vs. uncompressed 44/16, back when I was using stereo subwoofers in a heavily acoustically damped room. Even then, I could only tell when abx'ing.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#422

Post by astrange »

dom0 wrote: post #267
astrange wrote: post #141

Earlier quoted context omitted.

Images and audio are pretty similar, and sampling theory works for both - a low-pass filter on audio and a blur filter on images is the same. The difference is audio is "actually" bandlimited and frequency-based, but images are "actually" spatial. When you try using frequency math on images you get artifacts called ringing, which are easy to see with JPEGs or sharp scalers like Lanczos. Of course audio isn't really f…

> The difference is audio is "actually" bandlimited and frequency-based, but images are "actually" spatial. I.e. audio is sampled along one dimension, while images are sampled along two dimensions. Note that frequency-domain considerations play a crucial role in all optical design, including imaging sensors.

It's a little more than that. A sine wave originates in the frequency domain but actually sounds like something, but images originating in the frequency domain are just noise and not pictures of anything.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#423

Post by astrange »

kuschku wrote: post #219
astrange wrote: post #150

Earlier quoted context omitted.

It doesn't matter what resolution the color is stored at, as long as the high frequencies are the same as the Y channel. You won't have lost anything. Of course, cross-channel intra prediction would work better[1] but 4:2:0 is pretty good quality considering you can throw out 3/4 the pixels. [1] https://people.xiph.org/~unlord/spie_cfl.pdf

That’s again the same issue. Nice theory, and theoretically is true, but all real algorithms also subsample high frequencies, and scale them back up with nearest-neighbor. The same issue happens with audio. Nice theory, completely broken realistic implementations.

It's true that nearest neighbor is bad, but the important part is the YUV->RGB conversion. It distributes the missing high frequencies out of the Y channel into all three RGB images.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#424

Post by chaboud »

stephen_g wrote: post #371
chaboud wrote: post #274

So, having come from an image-processing background to put in 15 years of experience at audio processing companies, I've seen the xiph arguments, or something like them, several times. Heck, I worked for Sony (where that precious 22KHz cliff was made) for close to ten years... in professional media... many of those years with Sony professional audio people. And the "44.1KHz is enough" or "48KHz" is enough" people are…

All that still doesn't explain why in properly controlled double blind trials, people still haven't been able to demonstrate the ability to distinguish between different sample rates above 44.1kHz though...

Citations? I'm happy to read any research you have. (You can also come over, crack a beer, and record balloon pops and acoustic instruments... and an electric guitar... and electric kazoo.)

The xiph-cited studies I've seen show an identification of difference and a preference for... MP3. Hey, we want what we want.

Otherwise, go read Von Békésy's work for the foundation, established in the pre-digital era, but transferable if you understand digital audio.

For recognition of difference in high res audio, see:

Reiss - https://qmro.qmul.ac.uk/xmlui/bitstream/handle/123456789/134...

...And the papers referenced.

It's an interesting meta analysis and a good survey of the last 20 years of publication on the subject.

If you have some properly controlled double blind trials that show no discrimination ability, I'd be happy to read them. I'll admit that I haven't conducted statistically sufficient tests. I have, however, double-blinded (via software pseudo-random sample randomization).

Like I said, though, I've got work to do. Do some listening. Read some papers.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#425

Post by gbog »

jahnu wrote: post #18

I've said it before, this video demo is one of the very best I've ever seen. https://xiph.org/video/vid2.shtml So well prepared, so well presented, so little that could be removed without ruining it. I aspire to do such good demos but always fall so short.

Well I disagree. The background music on transitional slides can be removed. The rethorical questions ("let's pretend we do not know about digital audio") are just time fillers. Waving the hands toward an inscrustation looks as silly as the meteo girls "playing with flies in front of a green screen" on all TVs worldwide.

It is the same with most "well-written" articles in newspapers nowadays. We do not even feel it but its just canned food, a lot of jelly and chemical taste enhancer but the amount of real meat inside is near zero.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#426

Post by drather19 »

72deluxe wrote: post #282
lz400 wrote: post #270

Earlier quoted context omitted.

Yes, I've heard people putting the threshold in ~192kbps. Above that it's pretty much impossible these days. I can also tell the difference in 128kpbs, although sometimes it's a bit of nitpicking (can only hear differences in the sounds of hihats and things like that)

I think the type of music you are listening to assists with being able to differentiate. To me (much rock, blues, guitar music) 128kbps MP3 sounds like somebody chewed it first. Cymbals and bizarre snares that sound like the snare is now made of paper indicate the low bitrate. But 256+ and I certainly cannot tell the difference reliably.

When I was considering Tidal vs. Spotify in the past, I ran across the ABX tests here:

http://abx.digitalfeed.net/list.html

Pretty much found the same thing for myself at 256+.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#427

Post by arrrvalue »

romwell wrote: post #413
arrrvalue wrote: post #228

Earlier quoted context omitted.

It's not obvious that 2 channels of recorded audio aren't sufficient to recreate a convincing stereo image; suggesting that I'm seeking the equivalent of VR is specious. And you haven't answered my question about the array of 20kHz tone generators. In fact, NOBODY has, and yet the question has been down-voted! How is that even possible? Posing a novel experiment which might invalidate the populist view considered har…

>TFA's author is not active in the field of advancing man's ability to recreate live music more convincingly, AFAIK; he writes codecs As your other questions have been addressed by others, I simply would like to point out that this seems to be quite an arrogant stance to have. The development of codecs has a lot to do with understanding of how the humans perceive sound, and how to effectively encode and reproduce sou…

> Therefore, advancing the codecs does advance man's ability to recreate live music more convincingly.

Only where bandwidth and storage are constrained. If we're trying to push the state of the art, it's not going to be with a Zoom H2N.

The best music reproduction systems use lossless compression. Psychoacoustic compression does NOT get us closer to the original performance. I'm stating this as someone who gets 5 out of 5 correct, every time, on the NPR test:

http://www.npr.org/sections/therecord/2015/06/02/411473508/h...

(I'm ignoring the Suzanne Vega vocal-only track due to both its absence of musical complexity and use as test content during the development of the MP3 algorithm.)

While I appreciate xiphmont's codec work, I am dismissive of his open attempt to steer research and commerce in this area.

Why is his article posted as "neil-young.html"? Is that really fair?

> If you want to make a claim that this is somehow relevant to the question, you need to argue why, with sources - or simply ask the author, who might just answer.

Please see chaboud's excellent post above, referencing the work of Georg von Bekesy.

> Your last question is an example of one that rightly deserves to be downvoted

You're referring to my array-of-20kHz-tone-generators experiment? Sorry I don't know the answer, but I haven't done the experiment myself; I was hoping someone here had! Where's the appeal to emotion, though? If the experiment shows a higher sample rate is necessary (that's the whole point of the experiment) it's germane.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#428

Post by initself »

jackhack wrote: post #375
Mediterraneo10 wrote: post #330

Earlier quoted context omitted.

The loudness war is a matter of degree. Sure, steps have been taken so that we maybe won't see another Death Magnetic where the compression has resulted in outright ear-bleeding distortion. But when most music today is listened to from portable devices in loud environments, it’s hard to believe that we are ever again going back to the level of dynamic range common before the loudness war. As I said, even some classic…

Add to this the 'Bass arms race' happening in the past 15 years. It is especially noticeable if one listens to "modern" vs older CDs vs the radio. I suppose Producers now feel compelled to exercise subwoofers and thump the audience, or compensate for crappy earbuds in the target audience, or maybe that's just what people want because even radio commercials are complicit -- it's difficult to listen to someone talk wit…

Sometimes car head units have an undocumented bass and treble boost, so flat per the settings on the unit is far from flat. The kinds of compensations you are making get the unit closer to flat when it is a unit of configured with undocumented tuning. You could measure your head unit to find out.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#429

Post by romwell »

arrrvalue wrote: post #427
romwell wrote: post #413

Earlier quoted context omitted.

>TFA's author is not active in the field of advancing man's ability to recreate live music more convincingly, AFAIK; he writes codecs As your other questions have been addressed by others, I simply would like to point out that this seems to be quite an arrogant stance to have. The development of codecs has a lot to do with understanding of how the humans perceive sound, and how to effectively encode and reproduce sou…

> Therefore, advancing the codecs does advance man's ability to recreate live music more convincingly. Only where bandwidth and storage are constrained. If we're trying to push the state of the art, it's not going to be with a Zoom H2N. The best music reproduction systems use lossless compression. Psychoacoustic compression does NOT get us closer to the original performance. I'm stating this as someone who gets 5 out…

>Only where bandwidth and storage are constrained

I.e. everywhere in this universe. There is not such thing as unlimited bandwidth/storage. Gains that codecs give allow us to record information that otherwise would be lost.

>If we're trying to push the state of the art, it's not going to be with a Zoom H2N.

I wish I could see the future so clearly!

I only have guesses, and my guess tells me that audio captured from 10 Zoom H2N's at 48kHz will store more information than audio from a single microphone at 480kHz. Current "state of the art" seems to use fewer channels. An advance in the state of the art in the direction of utilizing more sources seems more than feasible to me.

>Psychoacoustic compression does NOT get us closer to the original performance

I think you have missed my point. An uncompressed source is obviously not going to be better than the lossy-compressed data.

However, we do not live in a world of infinite resources. Given the constraints, compression offers new possibilities.

At the same space/bandwidth, you can have, e.g.:

- uncompressed audio from a single source

- compressed audio from 5x many sources

- compressed audio from 2x sources, plus some other data which affects the perception of the sound (???)

This plays right into your question "Why are we only considering bitrate/frequency?" - we don't. Compression offers more flexibility in making other directions viable.

This is why I believe that codec research is important for advances of the state of the art.

>I am dismissive of his open attempt to steer research and commerce in this area.

In what area exactly? What research? He is not "steering research", he is educating the less knowledgeable general public. So far, your dismissive attitude can also be applied verbatim to anyone who explains why super-thick-golden-cables from MonstrousCable(tm) are a waste of money.

>> Your last question is an example of one that rightly deserves to be downvoted >You're referring to my array-of-20kHz-tone-generators experiment?

No, I was referring to this:

>Why aren't posts in support of music piracy down-voted (read above)?

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#430

Post by arrrvalue »

romwell wrote: post #429
arrrvalue wrote: post #427

Earlier quoted context omitted.

> Therefore, advancing the codecs does advance man's ability to recreate live music more convincingly. Only where bandwidth and storage are constrained. If we're trying to push the state of the art, it's not going to be with a Zoom H2N. The best music reproduction systems use lossless compression. Psychoacoustic compression does NOT get us closer to the original performance. I'm stating this as someone who gets 5 out…

>Only where bandwidth and storage are constrained I.e. everywhere in this universe. There is not such thing as unlimited bandwidth/storage. Gains that codecs give allow us to record information that otherwise would be lost. >If we're trying to push the state of the art, it's not going to be with a Zoom H2N. I wish I could see the future so clearly! I only have guesses, and my guess tells me that audio captured from 1…

xiphmont's primary goal appears to be to stop Neil Young from selling 24/192 audio to the general public; that's why he called the page neil-young.html. Sure, few buyers have the ears or equipment to pursue anything beyond the compact disc.

The problem is that many readers of neil-young.html will come away thinking they understand human hearing and digital sampling, when in fact the article is far too sparse on details to understand either; there is no discussion of how sounds are located in 3D space, or of how phase information is recovered. It is amazing that you can completely cover one ear, rub your fingers together behind your head and precisely pinpoint where your fingers are. It is also amazing that "Sampling doesn't affect frequency response or phase" but xiphmont doesn't explain this at all.

And then there's this lovely quote:

"It's true enough that a properly encoded Ogg file (or MP3, or AAC file) will be indistinguishable from the original at a moderate bitrate."

which is provably wrong. I can very reliably pick the uncompressed WAV each try when compared against 320kbps MP3.

My attitude is in support of furthering research in the area of live sound reproduction. As I've said, we are VERY far away right now. It is foolish to believe we understand human musical perception completely today. We cannot even replicate a simple cymbal strike with today's recording and playback technology.

I would encourage the curious to stand in the center of an outdoor arc of 100 horn players, like this (feel free to skip first 48 seconds):

https://www.youtube.com/watch?v=2EDIDCdy5Es

Once you experience that live, try to figure out how to replicate the input to your two ears. You can't, without 100 brass players.

Interestingly, these two examples of trumpet and cymbal have significant ultrasonic frequency content:

https://www.cco.caltech.edu/~boyk/spectra/spectra.htm

I don't believe it's a coincidence.

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