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> AAC and other newer audio codecs can produce better quality than MP3, but the difference is only significant at low bitrates AFAIR this is not correct (it's

> AAC and other newer audio codecs can produce better quality than MP3, but the difference is only significant at low bitrates AFAIR this is not correct (it's based on the Opus marketing page). In the last decade, interest in transparent bitrates (192+ kb) has faded, so it's hard to find listening tests. A few blind tests on the Hydrogenaudio page¹ report MP3 to be inferior to AAC at 192 kbps. A research reports² that the quality is the same (although if I understand correctly, looking at one analysis, results of noise/distortion are inconsistent, e.g. WAV being in some cases noisier/more distorted than MP3³). The same research references another research that find MP3 to be transparent at bitrates >= 256 Kbps. Something I remember is that MP3 spends a disproportionate amount of storage in order to encode frequencies > 16 Khz. This may explain why in some tests, it performs worse in mid-high bitrates (160/192 Kbps), although I don't know the technical details. ¹=https://hydrogenaud.io/index.php/board,40.0.html https://hydrogenaud.io/index.php/board,40.0.html ²=https://www.hindawi.com/journals/ijdmb/2019/8265301 https://www.hindawi.com/journals/ijdmb/2019/8265301 ³=https://www.hindawi.com/journals/ijdmb/2019/8265301/fig2 https://www.hindawi.com/journals/ijdmb/2019/8265301/fig2

earthnail 3y ago
Most encoders apply a low pass filter to cut off frequencies above 16kHz. Some do it above 18kHz but most choose 16kHz as default setting. This is common in all lossy codecs - mp3, aac etc.
- pizza234 3y ago
  It depends on the bitrate. AFAIR, LAME applies at 16 KHz cutoff at 128 kbps, and 17 Khz at 160 kbps. I don't have data about the others, but AFAIK a similar approach should apply. I'm not able to hear above 16 Khz. I've tried only once an experiment with another person, and they were definitely able to discern the difference.
fsiefken 3y ago
HE-AACv2 is better at low bitrates (spoken podcasts) then mp3. ffmpeg -i input.wav -c:a libfdk_aac -vbr 3 -b:a 32k -profile:a aac_he_v2 output.m4a There is also xHE-AAC https://gitlab.com/ecodis/exhale https://gitlab.com/ecodis/exhale https://www.mainconcept.com/hubfs/PDFs/User%20Guides/MainConcept%20xHE-AAC%20Encoder%20Plug-In%20for%20FFmpeg%20User%20Guide.pdf https://www.mainconcept.com/hubfs/PDFs/User%20Guides/MainCon...
mrob 3y ago
I was listening to some of the LAME quality test samples[0] and I found that the hi-hat pre-echo test sounds worse at 160kbps than at 128kbps (LAME 3.100, -q 0). I thought it might be because of the different low-pass filter frequency, but even with manually specified matching lowpass (16805Hz) for the 160kbps version the pre-echo sounds worse. The 128kbps version doesn't sound much like the original, but it's still a pleasant sound with hardly any pre-echo. The 160kbps version, even with the extra lowpass, has obvious and annoying pre-echo on the first hit. [0] https://lame.sourceforge.io/quality.php https://lame.sourceforge.io/quality.php
- kderbe 3y ago
  I can confirm this. I tested with 3.100.1 and the following encodes of hihat.wav: -q0 -b128 (b128) -q0 -b160 (b160) --preset cbr 128 (pc128) --preset cbr 160 (pc160) --preset 128 (pa128) --preset 160 (pa160) Using the Foobar2000 ABX comparator I was able to 5/5 ABX: wav vs. b128 wav vs. b160 b128 vs. b160 (this one was 7/8 ABX) wav vs. pa128 wav vs. pa160 b128 vs. pa128 (more difficult) pa128 vs. pa160 (more difficult) I did not successfully ABX b160 vs. pc160. I didn't do ABC/HR so I can't say for sure what my ranking would be, but my guess is: wav >> b128 > (b160 or pa160) > pa128
adql 3y ago
>Something I remember is that MP3 spends a disproportionate amount of storage in order to encode frequencies > 16 Khz. This may explain why in some tests, it performs worse in mid-high bitrates (160/192 Kbps), although I don't know the technical details. I wonder if just straight out filtering them would result in better 160Kbps MP3s, it's not like most people can hear them...
- Vecr 3y ago
  LAME does by default.
gwbas1c 3y ago
I did an investigation into MP3 vs AAC. My tests were at 320kbps. https://andrewrondeau.com/blog/archive/2016-07 https://andrewrondeau.com/blog/archive/2016-07 Basically, MP3 is crap at 320kbps, and AAC is somewhat better. The problem is that both formats roll off high frequencies. It's fine if you're listening in a car, through cheap speakers, on a noisy plane, aren't sensitive to higher frequencies, ect, ect. But, if you're in a quiet room with good speakers / headphones, and you have good ears, the high frequency roll off is noticeable.
- mrob 3y ago
  This appears to be visual comparisons of graphs of various automated measurements. Lossy codecs are designed to exploit weaknesses of human hearing, so the only way to test if they're working as intended is with listening tests. This is most conveniently done with ABX testing software. If that high frequency roll off is really noticeable you should be able to produce a statistically significant result. Here's an online ABX test of 320kbps MP3 using a modern encoder: http://abx.digitalfeed.net/lame.320.html http://abx.digitalfeed.net/lame.320.html Very few people are capable of hearing the difference, and even then only in difficult-to-encode samples. I don't think it's reasonable to call something of this quality "crap".
  - gwbas1c 3y ago
    > Very few people are capable of hearing the difference, ... I don't think it's reasonable to call something of this quality "crap". But some people can tell the difference. Therefore, the roll off is crap. Granted, if you only give yourself ~3.5 bits / sample, MP3 is quite impressive for what it does.
    - mrob 3y ago
      The audible difference is mostly pre-echo and warbling noises, not low-pass filtering.
- pizza234 3y ago
  "Investigations" without blind tests are useless. Try a blind test (the website of the sibling post is very interesting) and you'll be surprised at the bitrate at which you'll fail to notice differences.
muziq 3y ago
MP3 above 16Khz is the sfb21 ( scale factor band 21) problem.. Can’t be solved without lots of bits being thrown at it..
- pizza234 3y ago
  Thank you, that's very interesting. Are more modern format less susceptible to this problem?

earthnail 3y ago

Most encoders apply a low pass filter to cut off frequencies above 16kHz. Some do it above 18kHz but most choose 16kHz as default setting. This is common in all lossy codecs - mp3, aac etc.

pizza234 3y ago
It depends on the bitrate. AFAIR, LAME applies at 16 KHz cutoff at 128 kbps, and 17 Khz at 160 kbps. I don't have data about the others, but AFAIK a similar approach should apply. I'm not able to hear above 16 Khz. I've tried only once an experiment with another person, and they were definitely able to discern the difference.

fsiefken 3y ago

HE-AACv2 is better at low bitrates (spoken podcasts) then mp3. ffmpeg -i input.wav -c:a libfdk_aac -vbr 3 -b:a 32k -profile:a aac_he_v2 output.m4a There is also xHE-AAC https://gitlab.com/ecodis/exhale https://gitlab.com/ecodis/exhale https://www.mainconcept.com/hubfs/PDFs/User%20Guides/MainConcept%20xHE-AAC%20Encoder%20Plug-In%20for%20FFmpeg%20User%20Guide.pdf https://www.mainconcept.com/hubfs/PDFs/User%20Guides/MainCon...

mrob 3y ago

I was listening to some of the LAME quality test samples[0] and I found that the hi-hat pre-echo test sounds worse at 160kbps than at 128kbps (LAME 3.100, -q 0). I thought it might be because of the different low-pass filter frequency, but even with manually specified matching lowpass (16805Hz) for the 160kbps version the pre-echo sounds worse. The 128kbps version doesn't sound much like the original, but it's still a pleasant sound with hardly any pre-echo. The 160kbps version, even with the extra lowpass, has obvious and annoying pre-echo on the first hit. [0] https://lame.sourceforge.io/quality.php https://lame.sourceforge.io/quality.php

kderbe 3y ago
I can confirm this. I tested with 3.100.1 and the following encodes of hihat.wav: -q0 -b128 (b128) -q0 -b160 (b160) --preset cbr 128 (pc128) --preset cbr 160 (pc160) --preset 128 (pa128) --preset 160 (pa160) Using the Foobar2000 ABX comparator I was able to 5/5 ABX: wav vs. b128 wav vs. b160 b128 vs. b160 (this one was 7/8 ABX) wav vs. pa128 wav vs. pa160 b128 vs. pa128 (more difficult) pa128 vs. pa160 (more difficult) I did not successfully ABX b160 vs. pc160. I didn't do ABC/HR so I can't say for sure what my ranking would be, but my guess is: wav >> b128 > (b160 or pa160) > pa128

adql 3y ago

>Something I remember is that MP3 spends a disproportionate amount of storage in order to encode frequencies > 16 Khz. This may explain why in some tests, it performs worse in mid-high bitrates (160/192 Kbps), although I don't know the technical details. I wonder if just straight out filtering them would result in better 160Kbps MP3s, it's not like most people can hear them...

Vecr 3y ago
LAME does by default.

gwbas1c 3y ago

I did an investigation into MP3 vs AAC. My tests were at 320kbps. https://andrewrondeau.com/blog/archive/2016-07 https://andrewrondeau.com/blog/archive/2016-07 Basically, MP3 is crap at 320kbps, and AAC is somewhat better. The problem is that both formats roll off high frequencies. It's fine if you're listening in a car, through cheap speakers, on a noisy plane, aren't sensitive to higher frequencies, ect, ect. But, if you're in a quiet room with good speakers / headphones, and you have good ears, the high frequency roll off is noticeable.

mrob 3y ago
This appears to be visual comparisons of graphs of various automated measurements. Lossy codecs are designed to exploit weaknesses of human hearing, so the only way to test if they're working as intended is with listening tests. This is most conveniently done with ABX testing software. If that high frequency roll off is really noticeable you should be able to produce a statistically significant result. Here's an online ABX test of 320kbps MP3 using a modern encoder: http://abx.digitalfeed.net/lame.320.html http://abx.digitalfeed.net/lame.320.html Very few people are capable of hearing the difference, and even then only in difficult-to-encode samples. I don't think it's reasonable to call something of this quality "crap".
- gwbas1c 3y ago
  > Very few people are capable of hearing the difference, ... I don't think it's reasonable to call something of this quality "crap". But some people can tell the difference. Therefore, the roll off is crap. Granted, if you only give yourself ~3.5 bits / sample, MP3 is quite impressive for what it does.
  - mrob 3y ago
    The audible difference is mostly pre-echo and warbling noises, not low-pass filtering.
pizza234 3y ago
"Investigations" without blind tests are useless. Try a blind test (the website of the sibling post is very interesting) and you'll be surprised at the bitrate at which you'll fail to notice differences.

muziq 3y ago

MP3 above 16Khz is the sfb21 ( scale factor band 21) problem.. Can’t be solved without lots of bits being thrown at it..

pizza234 3y ago
Thank you, that's very interesting. Are more modern format less susceptible to this problem?