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Public AAC Listening Test @ ~96 kbps [July 2011]: Results, Results and post-test discussion
IgorC
post Aug 23 2011, 19:56
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After the long time of preparations, discussions and realization of the test the results are finally here.

http://listening-tests.hydrogenaudio.org/i...-a/results.html

Summary: Apple won, FhG is the second, Coding Technologies is the third and Nero is the last

I appreciate all people who has supported the test and participated in it.

This post has been edited by IgorC: Aug 23 2011, 20:12
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benski
post Aug 23 2011, 20:18
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It would be interesting to do a rank-sum analysis comparing each pair of encoders. Although the numeric values assigned by the listener seem like legitimate statistical data, the only real value is whether or not a listener ranked one encoder higher or lower than another.
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Garf
post Aug 23 2011, 20:27
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QUOTE (benski @ Aug 23 2011, 21:18) *
It would be interesting to do a rank-sum analysis comparing each pair of encoders. Although the numeric values assigned by the listener seem like legitimate statistical data, the only real value is whether or not a listener ranked one encoder higher or lower than another.


Completely and utterly false. We're asking to grade on a reference scale, compare to a low anchor, and judge the severity of distortions, not whether codecs are better than others.

If you're going to claim this only "seems like legitimate", you better back up that statement. Specifically, why the interval scale here (used in each and every previous test) suddenly has to be abandoned for an ordinal scale, or why we're dropping the tracking of ITU-R BS.1116-1 methodology that's generally done in these tests. Are you saying the ITU methodology only "seems like legitimate"?
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benski
post Aug 23 2011, 20:54
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QUOTE (Garf @ Aug 23 2011, 15:27) *
QUOTE (benski @ Aug 23 2011, 21:18) *
It would be interesting to do a rank-sum analysis comparing each pair of encoders. Although the numeric values assigned by the listener seem like legitimate statistical data, the only real value is whether or not a listener ranked one encoder higher or lower than another.


Completely and utterly false. We're asking to grade on a reference scale, compare to a low anchor, and judge the severity of distortions, not whether codecs are better than others.

If you're going to claim this only "seems like legitimate", you better back up that statement. Specifically, why the interval scale here (used in each and every previous test) suddenly has to be abandoned for an ordinal scale, or why we're dropping the tracking of ITU-R BS.1116-1 methodology that's generally done in these tests. Are you saying the ITU methodology only "seems like legitimate"?


Sorry, I only now read the caveat in the results page - "The graphs are a simple ANOVA analysis over all submitted and valid results. This is compatible with the graphs of previous listening tests, but should only be considered as a visual support for the real analysis.". My initial reaction was to the box-plot graphs, not to the analysis at the bottom of the page.

The Friedman ANOVA analysis (bootstrap or not) are using rank-based testing.

This post has been edited by benski: Aug 23 2011, 21:00
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Garf
post Aug 23 2011, 21:11
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QUOTE (benski @ Aug 23 2011, 21:54) *
The Friedman ANOVA analysis (bootstrap or not) are using rank-based testing.


(Blocked) ANOVA is a parametric, means-based test. FRIEDMAN is the name of the utility (which unsurprisingly, also supports Friedman analysis). The result posted is means-based, not rank-based. It's there mostly to allow referencing with older tests and with other statistical packages, which are more likely to support normal blocked ANOVA than the nonparametric variants. Friedman wasn't developed further because it doesn't allow p-value step-down without losing a significant amount of power for many comparisons, and because for high-bitrate tests it is no longer clear the results are normally distributed. That's exactly what lead to bootstrap.

This post has been edited by Garf: Aug 23 2011, 21:48
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Posts in this topic
- IgorC   Public AAC Listening Test @ ~96 kbps [July 2011]: Results   Aug 23 2011, 19:56
- - benski   It would be interesting to do a rank-sum analysis ...   Aug 23 2011, 20:18
|- - Garf   QUOTE (benski @ Aug 23 2011, 21:18) It wo...   Aug 23 2011, 20:27
||- - benski   QUOTE (Garf @ Aug 23 2011, 15:27) QUOTE (...   Aug 23 2011, 20:54
||- - Garf   QUOTE (benski @ Aug 23 2011, 21:54) The F...   Aug 23 2011, 21:11
|- - C.R.Helmrich   QUOTE (benski @ Aug 23 2011, 21:18) ... w...   Aug 23 2011, 20:42
||- - Garf   QUOTE (C.R.Helmrich @ Aug 23 2011, 21:42)...   Aug 23 2011, 20:47
|||- - lvqcl   QUOTE (Garf @ Aug 23 2011, 23:47) Basical...   Aug 27 2011, 20:22
|||- - no404error   QUOTE (lvqcl @ Aug 27 2011, 22:22) CVBR, ...   Sep 4 2011, 04:01
||- - benski   QUOTE (C.R.Helmrich @ Aug 23 2011, 15:42)...   Aug 23 2011, 20:52
|- - IgorC   QUOTE (benski @ Aug 23 2011, 16:18) It wo...   Aug 23 2011, 21:01
|- - benski   QUOTE (IgorC @ Aug 23 2011, 16:01) QUOTE ...   Aug 23 2011, 21:07
|- - IgorC   QUOTE (benski @ Aug 23 2011, 17:07) Actua...   Aug 23 2011, 21:11
- - IgorC   I should also mention that I've participated i...   Aug 23 2011, 21:30
- - zima   Maybe there could be a legend for X-axis, the abbr...   Aug 23 2011, 21:37
- - lvqcl   It is interesting that QT tvbr and cvbr encoded fi...   Aug 23 2011, 22:05
- - IgorC   zima, will fix it later. QUOTE (lvqcl @ Au...   Aug 23 2011, 22:11
- - Alexxander   Thanks to all who participated in this test and to...   Aug 23 2011, 22:31
|- - Garf   QUOTE (Alexxander @ Aug 23 2011, 23:31) I...   Aug 23 2011, 23:02
- - Dakeryas   Many thanks for the test ! Interesting to not...   Aug 23 2011, 23:11
- - IgorC   I've noticed that previous version of Nero 1.0...   Aug 23 2011, 23:51
- - Gornot   To be perfectly honest, I am surprised that FhG di...   Aug 24 2011, 00:29
- - /mnt   Interesting results, I gotta see if the pre-echo h...   Aug 24 2011, 01:23
- - kennedyb4   If it is fair to say that many of the samples were...   Aug 24 2011, 01:42
- - Sebastian Mares   It appears to me that the low anchor was way too b...   Aug 24 2011, 07:29
|- - Garf   QUOTE (Sebastian Mares @ Aug 24 2011, 08...   Aug 24 2011, 09:35
|- - Nezmer   QUOTE (Garf @ Aug 24 2011, 10:35) Probabl...   Aug 24 2011, 11:35
|- - Garf   QUOTE (Nezmer @ Aug 24 2011, 12:35) QUOTE...   Aug 24 2011, 12:46
|- - Nezmer   QUOTE (Garf @ Aug 24 2011, 13:46) QUOTE (...   Aug 24 2011, 18:26
- - greynol   I was wondering the same thing.   Aug 24 2011, 07:49
- - C.R.Helmrich   Some bit-rate statistics which were presented in p...   Aug 24 2011, 18:27
|- - Garf   QUOTE (C.R.Helmrich @ Aug 24 2011, 19:27)...   Aug 25 2011, 07:29
- - Zarggg   Just looking for a quick verification on whether I...   Aug 25 2011, 18:06
|- - IgorC   QUOTE (Zarggg @ Aug 25 2011, 14:06) Am I ...   Aug 25 2011, 18:28
- - greynol   CVBR and TVBR are statistically tied. One did not...   Aug 25 2011, 18:12
|- - Zarggg   QUOTE (greynol @ Aug 25 2011, 13:12) CVBR...   Aug 25 2011, 22:47
|- - Garf   QUOTE (greynol @ Aug 25 2011, 19:12) CVBR...   Aug 26 2011, 07:20
- - greynol   That assumes facts not in evidence.   Aug 25 2011, 19:04
- - Gecko   First, thank you IgorC and everyone involved! ...   Aug 25 2011, 20:24
|- - IgorC   QUOTE (Gecko @ Aug 25 2011, 16:24) First,...   Aug 26 2011, 03:30
||- - mjb2006   QUOTE (IgorC @ Aug 25 2011, 20:30) I do n...   Aug 26 2011, 05:18
||- - IgorC   QUOTE (mjb2006 @ Aug 26 2011, 01:18) Anyw...   Aug 26 2011, 05:24
|- - Garf   QUOTE (Gecko @ Aug 25 2011, 21:24) a) Do ...   Aug 26 2011, 07:16
|- - IgorC   QUOTE (Garf @ Aug 26 2011, 03:16) Always ...   Aug 26 2011, 08:51
- - mjb2006   Even though I sent in results, they didn't get...   Aug 25 2011, 22:50
- - Gecko   Thank you IgorC and Garf for answering my question...   Aug 26 2011, 10:28
|- - IgorC   QUOTE (Gecko @ Aug 26 2011, 06:28) Given ...   Aug 26 2011, 11:20
||- - Garf   QUOTE (IgorC @ Aug 26 2011, 12:20) QUOTE ...   Aug 27 2011, 17:48
|- - Garf   QUOTE (Gecko @ Aug 26 2011, 11:28) In the...   Aug 27 2011, 17:39
- - IgorC   I found the first and the last graphs to be partic...   Aug 27 2011, 21:46
|- - lvqcl   QUOTE (IgorC @ Aug 28 2011, 00:46) I thin...   Aug 27 2011, 22:20
- - IgorC   Yeah   Aug 27 2011, 22:39
- - IgorC   BTW if someone want to organize the next public te...   Oct 1 2011, 20:21
- - jukkap   How about 48kbps HE AAC ? Or low bitrate multiform...   Oct 1 2011, 20:49
|- - IgorC   QUOTE (jukkap @ Oct 1 2011, 16:49) How ab...   Oct 10 2011, 23:17
|- - jukkap   QUOTE (IgorC @ Oct 10 2011, 23:17) The la...   Oct 20 2011, 10:04
- - IgorC   Well, the last time we have tested LC-AAC encoders...   Oct 1 2011, 21:58
- - jukkap   QUOTE (IgorC @ Oct 1 2011, 22:58) Can You...   Oct 2 2011, 05:10
- - IgorC   Late but still here. Some participants have answ...   Oct 23 2011, 07:14


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