3 ms·

See "Why not use graphs / frequency analysis to compare codecs?" https://wiki.hydrogenaud.io/index.php?title=FAQ#:~:text=Why%20not%20use%20graphs https://wiki.h

by lazka 2y ago

See "Why not use graphs / frequency analysis to compare codecs?" https://wiki.hydrogenaud.io/index.php?title=FAQ#:~:text=Why%20not%20use%20graphs https://wiki.hydrogenaud.io/index.php?title=FAQ#:~:text=Why%... "I decided that analysis should focus on the higher, more conventional rates – 48k and 44k1" - opus is always 48khz, so that doesn't mean much.

mrob 2y ago
This. Your ears are not an oscilloscope. Lossy audio codecs are designed to exploit two major weaknesses in human hearing: 1. Poor sensitivity in bass and treble. See: https://en.wikipedia.org/wiki/Equal-loudness_contour https://en.wikipedia.org/wiki/Equal-loudness_contour 2. Limited ability to hear multiple sounds simultaneously, or almost simultaneously. See: https://en.wikipedia.org/wiki/Auditory_masking https://en.wikipedia.org/wiki/Auditory_masking Bernhard Seeber has some videos on Youtube with demonstrations of auditory masking: https://www.youtube.com/watch?v=R9UZnMsm9o8 https://www.youtube.com/watch?v=R9UZnMsm9o8 https://www.youtube.com/watch?v=bU0_Kaj7cPk https://www.youtube.com/watch?v=bU0_Kaj7cPk The only fair way to evaluate lossy codecs is with double blind listening tests.
- Arech 2y ago
  The problem with these weaknesses is that they are different in each human being. For me listening an mp3 is like a sanding an ear, while some don't even hear the difference between it and a live performance.
  - mrob 2y ago
    Can you ABX it? https://abx.digitalfeed.net/lame.320.html https://abx.digitalfeed.net/lame.320.html
  - jpc0 2y ago
    > For me listening an mp3 is like a sanding an ear There is such a broad spectrum in thr word mp3 that you need to be more specific. I can absolutely pick the difference between certian high bitrate mp3 encodings and wav files, however a different mp3 with exactly the same bitrate, effectively indistinguishable. Bad mp3 encoding is a problem, not one I have experienced recently though. I think the bigger issue is people will rip a music video from youtube, then instead of extracting the existing audio stream into it's own container will reencode it. Mp3->mp3 encoding will be lossy just like any other encoder.
- concerndc1tizen 2y ago
  I wonder how many people there are, that don't have these weaknesses. And who are therefore forced to hear terrible audio because the compression method only considers the majority.
  - mrob 2y ago
    If people have notches in their hearing sensitivity at low or mid frequencies, sounds at those frequencies might fail to mask other sounds as expected. You could simulate this by applying notch filters to otherwise transparent lossy audio and seeing if it exposes compression artifacts. But I think this kind of hearing loss is uncommon. Normal age-related hearing loss does not cause any problems with lossy audio compression.

by lazka 2y ago

mrob 2y ago

This. Your ears are not an oscilloscope. Lossy audio codecs are designed to exploit two major weaknesses in human hearing: 1. Poor sensitivity in bass and treble. See: https://en.wikipedia.org/wiki/Equal-loudness_contour https://en.wikipedia.org/wiki/Equal-loudness_contour 2. Limited ability to hear multiple sounds simultaneously, or almost simultaneously. See: https://en.wikipedia.org/wiki/Auditory_masking https://en.wikipedia.org/wiki/Auditory_masking Bernhard Seeber has some videos on Youtube with demonstrations of auditory masking: https://www.youtube.com/watch?v=R9UZnMsm9o8 https://www.youtube.com/watch?v=R9UZnMsm9o8 https://www.youtube.com/watch?v=bU0_Kaj7cPk https://www.youtube.com/watch?v=bU0_Kaj7cPk The only fair way to evaluate lossy codecs is with double blind listening tests.

Arech 2y ago
The problem with these weaknesses is that they are different in each human being. For me listening an mp3 is like a sanding an ear, while some don't even hear the difference between it and a live performance.
- mrob 2y ago
  Can you ABX it? https://abx.digitalfeed.net/lame.320.html https://abx.digitalfeed.net/lame.320.html
- jpc0 2y ago
  > For me listening an mp3 is like a sanding an ear There is such a broad spectrum in thr word mp3 that you need to be more specific. I can absolutely pick the difference between certian high bitrate mp3 encodings and wav files, however a different mp3 with exactly the same bitrate, effectively indistinguishable. Bad mp3 encoding is a problem, not one I have experienced recently though. I think the bigger issue is people will rip a music video from youtube, then instead of extracting the existing audio stream into it's own container will reencode it. Mp3->mp3 encoding will be lossy just like any other encoder.
concerndc1tizen 2y ago
I wonder how many people there are, that don't have these weaknesses. And who are therefore forced to hear terrible audio because the compression method only considers the majority.
- mrob 2y ago
  If people have notches in their hearing sensitivity at low or mid frequencies, sounds at those frequencies might fail to mask other sounds as expected. You could simulate this by applying notch filters to otherwise transparent lossy audio and seeing if it exposes compression artifacts. But I think this kind of hearing loss is uncommon. Normal age-related hearing loss does not cause any problems with lossy audio compression.