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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

by anyfoo 9y ago

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.

kuschku 9y ago
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 example allocate almost the entire space for the frequencies around 4 to 8kHz, and drops then drops a certain percentage of the upper frequencies entirely. The article talks about uncompressed audio, but the topic he responds to is Apple choosing to sell 24bit/192kHz AAC lossy compressed audio. The author of the article is responding to a business decision, which has nothing to do with the actual topic of the article.
- astrange 9y ago
  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.
- cellularmitosis 9y ago
  Funny anecdote, I first became aware of this while watching Aliens. When the aliens cut the power and the set is bathed in the red of the emergency backup lights, the resolution of the video appears much worse.
BuuQu9hu 9y ago
> The article was arguing about 24bit/192kHz digital audio, not about what codecs do or don't do with it. That's the problem with the article. The audible improvement of 24/192 is noticeable AFTER compression not BEFORE. The article argues the latter point which is completely irrelevant.

by anyfoo 9y ago

kuschku 9y ago

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 example allocate almost the entire space for the frequencies around 4 to 8kHz, and drops then drops a certain percentage of the upper frequencies entirely. The article talks about uncompressed audio, but the topic he responds to is Apple choosing to sell 24bit/192kHz AAC lossy compressed audio. The author of the article is responding to a business decision, which has nothing to do with the actual topic of the article.

astrange 9y ago
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.
cellularmitosis 9y ago
Funny anecdote, I first became aware of this while watching Aliens. When the aliens cut the power and the set is bathed in the red of the emergency backup lights, the resolution of the video appears much worse.

BuuQu9hu 9y ago

> The article was arguing about 24bit/192kHz digital audio, not about what codecs do or don't do with it. That's the problem with the article. The audible improvement of 24/192 is noticeable AFTER compression not BEFORE. The article argues the latter point which is completely irrelevant.