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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)

#141

Post by astrange »

fusiongyro wrote: post #14
acchow wrote: post #7

Earlier quoted context omitted.

> Its playback fidelity is slightly inferior to 16/44.1 or 16/48, and it takes up 6 times the space. The article is highly technical. Does anyone have a way to describe this phenomenon intuitively?

Basically, the sampling theorem says you can reconstruct the exact waveform with a certain number of samples. Adding a bunch more samples bulks up the file, but you didn't need them to restore the exact waveform. However, the unnecessary samples are in the file between you and the next sample you do need. At high enough levels of waste this creates an I/O bottleneck that hampers performance. Another way to look at is…

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 frequency-based either, or else it would just be one sound repeated forever. So there's still ringing artifacts (called "pre-echo") and cymbals are the first to go in an MP3.

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

#142

Post by derefr »

lz400 wrote: post #140

There's a very straightforward practical reason why you might want to keep downloading 24/192. The people who put those together are on average "audiophile" snobs so the rips tend to be perfect, often from high quality sources like SACDs, hdtracks, etc. The source of the recording is usually the best master known for that record (special remastered editions, etc.). If you download mp3/spotify chances are the copy you…

Similarly, seeing 24/192 on a rip from an analogue source (e.g. vinyl) usually implies that a high-quality player+amp+ADC was used to digitize the album.

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

#143

Post by zaroth »

Const-me wrote: post #134

If the only thing you do with your music is listen, then yes, 24/192 delivers questionable value compared to the more popular 16/44.1 or 16/48 formats. However, all musicians I know use these high-rez formats internally. The reason for that, when you apply audio effects, especially complex VST ones, these discretization artifacts noticeably decrease the result quality. Maybe, the musicians who distribute their music…

TFA specifically addresses this and agrees 100% with you on it. Develop in 24/192, but ship in 16/48. Good point about supporting better downstream remixing!

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

#144

Post by flyinghamster »

arrrvalue wrote: post #138

and yet, we are nowhere near being able to electronically reproduce a live acoustic music performance. have you ever walked by a bunch of musical sound coming out of a room and thought to yourself, "wow, those live musicians sound great" only to discover it was just a stereo playing? nope. as engineers we will never solve this problem as long as the "44.1kHz is good enough" dogma is perpetuated. here's a question. wh…

In my own experience, the vast majority of consumer audio gear doesn't even take full advantage of 16/44.1. I've made live recordings of my classical chorus, and if I want it to be listenable on typical consumer gear, I have to apply a significant amount of dynamic range compression - otherwise, it will be either too quiet, or it won't handle the peaks when played at concert volume.

That being said, I'm using quite a bit less compression than the loudness-war-type mastering that is all too typical with pop music.

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

#145

Post by astrange »

kuschku wrote: post #62
anyfoo wrote: post #55

Earlier quoted context omitted.

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 qualit…

With video it’s not about bitrate, but Chroma Subsampling. Basically, mp4 and webm video only encodes the brightness channel Y at full resolution, and the color channels Pb Pr at half resolution. You can’t have mp4 or webm video without Chroma Subsampling, it’s defined in the codecs standard. Audio codecs do something very similar, cutting off a large percentage of the higher and lower frequencies. mp3 (and AAC) for…

Chroma subsampling is optional in AVC and HEVC and IMO we should stop using it for 480p or smaller video. Not because the information is important - color is usually bandlimited - but because all the decoders use the worst resampling algorithm to display it.

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

#146

Post by kazinator »

lz400 wrote: post #140

There's a very straightforward practical reason why you might want to keep downloading 24/192. The people who put those together are on average "audiophile" snobs so the rips tend to be perfect, often from high quality sources like SACDs, hdtracks, etc. The source of the recording is usually the best master known for that record (special remastered editions, etc.). If you download mp3/spotify chances are the copy you…

So, in other words: bite the bandwidth bullet and get the 192 material, but for Pete's sake, do yourself a favor and downsample to 44.1.

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

#147

Post by kazinator »

Const-me wrote: post #134

If the only thing you do with your music is listen, then yes, 24/192 delivers questionable value compared to the more popular 16/44.1 or 16/48 formats. However, all musicians I know use these high-rez formats internally. The reason for that, when you apply audio effects, especially complex VST ones, these discretization artifacts noticeably decrease the result quality. Maybe, the musicians who distribute their music…

I do not believe it. 24 bits is definitely needed for processing (better yet, use floating-point).

Not 192 kHz; no friggin' way.

Repeated processing through multiple blocks at a given sample rate does not produce cumulative discretization problems in the time domain; it's just not how the math works.

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

#148

Post by romwell »

arrrvalue wrote: post #138

and yet, we are nowhere near being able to electronically reproduce a live acoustic music performance. have you ever walked by a bunch of musical sound coming out of a room and thought to yourself, "wow, those live musicians sound great" only to discover it was just a stereo playing? nope. as engineers we will never solve this problem as long as the "44.1kHz is good enough" dogma is perpetuated. here's a question. wh…

>as engineers we will never solve this problem [reproduce a live acoustic music performance] as long as the "44.1kHz is good enough" dogma is perpetuated

It's the opposite. We are never going to solve this problem if we are going to focus on things that have nothing to do with the problem. Compare and contrast:

>as engineers we will never solve this problem as long as the "copper wires are good enough" dogma is perpetuated

Also, please read the article. The author specifically lists advances in audio tech they think are worthwhile to consider, such as surround sound. This actually addresses the problem you mentioned (reproducing the live performance) and the question you asked, i.e.

>here's a question. why are frequency and bit depth the only two variables under discussion here?

They are not, at least not in the article. Here it's because that's what's in the title, and not everyone gets to the end of the article.

Some comments do talk about the importance of having a good DAC for a good sound.

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

#149

Post by kazinator »

tzs wrote: post #83

What about for non-humans? Consider a dog that lives with a musician who plays, for example, trumpet. The musician plays the trumpet at home to practice, and also records his practices to review. A trumpet produces significant acoustic energy out to about 100 KHz [1]. When the musician plays live the dog hears a rich musical instrument. When the musician plays back his recordings, half the frequency range that the do…

> What about for non-humans?

The thing is, the higher sample rate data doesn't actually have a lot of the higher components after 20 kHz.

What the faster sample rate allows is to use a less aggressive filter.

Instead of a "brick wall" filter that rapidly cuts off after around 20 kHz, one with fewer poles can be used which rolls off more gently.

The higher sample rate ensures that there isn't any aliasing.

192 kHz audio does not reproduce flat up to 90 kHz.

(I'm going to gloss over the microphone used on the trumpet, or the loudspeakers which ultimately reproduce it.)

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

#150

Post by astrange »

kuschku wrote: post #60
TazeTSchnitzel wrote: post #53

Earlier quoted context omitted.

> 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 cal…

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

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