Live data from Hacker News

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

xiph.org

51–60 of 445 posts

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

#52

when I listen mp3s via 24/192 M-audio spdif to denon 1705 there is a huge differenc to just optical from the motherboard. why is that then?

There can be dozens of completely different reasons why that might be the case, without requiring inaudible frequencies to be involved.

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

#53
post #38

This article makes the same mistake that is done frequently with video. So, let’s look at a similar issue with video. Your display is likely only 720p, or 1080p, but a 4K video on youtube will still look a lot better, although technically it should have no visible difference. But the reality is, we don’t get uncompressed video, or uncompressed audio. We have a choice between audio or video compressed with lossy codec…

> Your display is likely only 720p, or 1080p, but a 4K video on youtube will still look a lot better, although technically it should have no visible difference.

Not at all, bitrate differences are audible.

> And just like you need 4K 4:2:0 mp4 video to get even close to the quality of uncompressed 1080p 4:4:4 video, you also need far higher sampling rate and depth of highly compressed audio to get a quality similar to 16bit/44.1kHz PCM.

…how so?

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

#54
post #45

Earlier quoted context omitted.

It's not that much different to think of than 480p vs 4K/2160p -- dramatically higher resolution, increasing the width and length of the 'grid' that sound is recorded into -- except that in the case of audio fidelity, quality after a certain point causes problems with playback systems, resulting in audible artifacts and distortion.

That analogy works if you modify it: - 480p vs 2160p is measuring the resolution of your cell phone propped up on a pillow at the other end of your living room - experimental evidence shows that your eyesight is not good enough to pick up on the increased resolution, you've maxed out your sensory perception - Your phone stutters trying to stream at 4k so the playback might actually be worse.

All good points! Indeed all that extra data makes the decode stage that much more difficult. Same happens with audio too, but high-res audio isn't nearly as bulky as video or nearly as resource-intensive to decode

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

#55
post #38

This article makes the same mistake that is done frequently with video. So, let’s look at a similar issue with video. Your display is likely only 720p, or 1080p, but a 4K video on youtube will still look a lot better, although technically it should have no visible difference. But the reality is, we don’t get uncompressed video, or uncompressed audio. We have a choice between audio or video compressed with lossy codec…

The article was arguing about 24bit/192kHz digital audio, not about what codecs do or don't do with it. If you need 24bit/192kHz with both inaudible frequencies and inaudible dynamic steps to make 16bit/48kHz music sound better at the same bitrate, then the parameters you've given to your codec suck.

Same for video. YouTube very likely allocates more bandwidth for 4k video than would be required for equivalent quality at lower resolutions, assuming that you are interested in higher overall quality (e.g. less artifacts) if you go through the trouble of 4k video. That's a conscious choice, not a technical necessity.

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

#56
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.

Wow, that was awesome!

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

#57
post #34
post #27

Earlier quoted context omitted.

We are not really talking about lossy codecs here, though, are we?

Ah, my mistake. But perhaps you could consider 24/192 -> 16/48 a lossy codec in this context; the same argument does apply, for the same reasons.

That way it does make sense, editing might require higher fidelity than we can perceive in the final project to avoid artifacts.

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

#58
post #22

FTA: "192kHz digital music files offer no benefits. They're not quite neutral either; practical fidelity is slightly worse. The ultrasonics are a liability during playback." I would expect the samples to be interpolated before the final DA conversion takes place, so no extra ultrasonics should be involved. And there would be filters for them anyway, we still have to use them for 44.1, 48, 96 etc.

But if you're filtering out ultrasonics, then you've guaranteed that the extra samples will be wasted. There won't be any difference in the reconstructed signal at all.

The extra bits mean you can change how you filter the sound later, depending on what range your headphones/speakers are capable of reproducing without distortion, or what your ears are capable of hearing.

Who knows, maybe technology or genetic changes will allow future humans to hear in a wider range than we do now. Those people might appreciate being able to hear what our music really sounded like.

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

#59
post #6
post #3

While the extra quality is lost on listeners, from experience I've found that super-HQ source material can change your results (for the better) when fed through distortion/compression/warming effects processors

Is that because of the HQ audio, or because the processing software introduces less artifacts at those sample rates/bit depths? I.e. could you get the same results by up-sampling CD quality audio?

For distortion and compression, the only possible difference I can think of is aliasing, and yeah you could just oversample your input, then downsample again on the way out. This is really really common in most professional plugins, often with an adjustable amount to balance quality and CPU usage.

I also have some gear that aliases at a volume you can't hear, but when you plug it into an analog distortion pedal, the aliasing in the high frequencies becomes apparent. This would be avoided if it had a higher sample rate so the aliasing was far out of the audible range.

For other sorts of effects like spectral processing, pitch shifting, the extra detail above 22khz really does make a difference, especially if pitching down.

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

#60
post #38

This article makes the same mistake that is done frequently with video. So, let’s look at a similar issue with video. Your display is likely only 720p, or 1080p, but a 4K video on youtube will still look a lot better, although technically it should have no visible difference. But the reality is, we don’t get uncompressed video, or uncompressed audio. We have a choice between audio or video compressed with lossy codec…

> Your display is likely only 720p, or 1080p, but a 4K video on youtube will still look a lot better, although technically it should have no visible difference. Not at all, bitrate differences are audible. > And just like you need 4K 4:2:0 mp4 video to get even close to the quality of uncompressed 1080p 4:4:4 video, you also need far higher sampling rate and depth of highly compressed audio to get a quality similar t…

> Not at all, bitrate differences are audible.

Even with the same bitrate, you’ll need 4K video to get quality comparable to uncompressed 1080p.

For example, mp4 defines that the brightness channel Y should be stored with full resolution, and the color channels Pb Pr should be stored at half resolution. So in a 4K mp4 video at lossless bitrate, the actual colors will only be stored at 1080p. This functionality is called Chroma Subsampling.

Audio Codecs do something very similar, causing these exact issues.

Post reply on HN