 Topic: ABX Result Calculation : Suggestion (Read 2915 times)
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## ABX Result Calculation : Suggestion ##### 2004-11-24 06:35:43
Is this way of calculation any good?

this is my suggestion: (to test codec's transparency)

at high bitrate such as 192kbps and above, its pretty hard to rate it!
so why not just use A , B & X test (which is available in foobar2000)

Formula = no. of wrong trials divided by no. right trials

Fix the trial to 10

if the result is 9/10, that means 1/9=0.11111, the codec is NOT transparent

if the result is 10/10,  0/10=0, the codec transparent probability is 0

if the result is 5/10, 5/5=1, the codec is transparent

if the result is 1/10, 9/1=9, the codec is NO DOUBT transparent

If the result is 0/10 (which is impossible), 10/0=......No DOUBT transparent

..............

## ABX Result Calculation : Suggestion ##### Reply #1 – 2004-11-25 08:15:21
Quote
(...)
if the result is 5/10, 5/5=1, the codec is transparent
(...)
[{POST_SNAPBACK}][/a]

Did you ever run any ABX program?

[a href="http://ff123.net/abx/abx.html]http://ff123.net/abx/abx.html[/url]
An encoded file is for sure transparent if pval < 0.05 (even below if ABX test is not sequential).
5/10 => pval = 0.624
In other word, 62% of chance that the tester is guessing.

## ABX Result Calculation : Suggestion ##### Reply #2 – 2004-11-25 10:04:09
Quote
An encoded file is for sure transparent if pval < 0.05 (even below if ABX test is not sequential).
5/10 => pval = 0.624
In other word, 62% of chance that the tester is guessing.
[a href="index.php?act=findpost&pid=256084"][{POST_SNAPBACK}][/a]

oops...thanks guru, I've used ABX in foobar2000, but I don't really understand the pval=XX%

## ABX Result Calculation : Suggestion ##### Reply #3 – 2004-11-25 10:13:16
Another precision:
0/10 doesn't mean transparency, but total failure. 9/10 is a pretty good result - not the opposite