Codecs and settings for 64kbit/s SE listening test, criticism required Options

[Serge Smirnoff]

As SoundExpert now has pretty stable flow of volunteer testers it is time to update codecs in all bitrate sections. After a short discussion at Russian bit-torrent tracker we decided to update 64-96-128-192-256-320 sections first. For the 64kbit/s section five codecs were chosen:

Fhg AAC (2012-06-24) - 59.2 kbit/s (fhgaacenc --vbr 2 se_ref.wav)
QAAC TVBR (v1.42) - 59.6 kbit/s (qaac --he -v56 se_ref.wav)
Nero AAC (v1.5.4.0) - 60.1 kbit/s (neroAacEnc.exe -q 0.25 -if se_ref.wav -of out.mp4)
Vorbis (Xiph 1.3.3) - 60.3 kbit/s (oggenc2.exe -q-0.3 se_ref.wav)
Opus (libopus 1.0.1) - 59.9 kbit/s (opusenc --bitrate 59 se_ref48.wav out.opus)
Conversion chain for Opus: 44.1/16 -->> 48/24(Audition CS6) -->> opusenc -->> foobar2000(48/24) -->> 44.1/16(Audition CS6)

Bitrates are calculated on the basis of nine SE test samples concatenated. Fortunately first two codecs have close values of resulting bitrates at their corresponding discrete quality settings. Other contenders were adjusted to have close values.

Did we miss something?

[yourlord]

How about, can we have a test worth performing?

If AAC, Vorbis, Opus, and MP3 are all statistically transparent at a given nominal bit rate then they are all audibly the SAME QUALITY at that bit rate. No one codec offers any audible benefit over the others at that point. There is nothing to gain in claiming to judge codec quality by adding distortion to their output and pretending it somehow matters in the real world.

I'm honestly not sure why this thread hasn't been locked/removed. It smells of snake oil and pixie dust, or at the least is ill-conceived. These "tests" of adulterated codec outputs offer us no relevant results on which to base any kind of rational discussion or decisions, other than how NOT to conduct a codec quality test. It can only serve to spread disinformation and ignorance. IMO it has no place on HA.

This post has been edited by yourlord: Oct 15 2012, 21:56

[Serge Smirnoff]

How about, can we have a test worth performing?

If AAC, Vorbis, Opus, and MP3 are all statistically transparent at a given nominal bit rate then they are all audibly the SAME QUALITY at that bit rate. No one codec offers any audible benefit over the others at that point. There is nothing to gain in claiming to judge codec quality by adding distortion to their output and pretending it somehow matters in the real world.

I'm honestly not sure why this thread hasn't been locked/removed. It smells of snake oil and pixie dust, or at the least is ill-conceived. These "tests" of adulterated codec outputs offer us no relevant results on which to base any kind of rational discussion or decisions, other than how NOT to conduct a codec quality test. It can only serve to spread disinformation and ignorance. IMO it has no place on HA.

Probably I should repeat once again - 32kbps and up to 128kbps SE listening tests are performed without artifacts amplification. The topic is devoted to codecs and settings for 64kbps listening test.