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Randomizing file names, to compare lossy files etc.
Brand
post Dec 26 2012, 21:05
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As you may know, comparing various lossy files (by ABXing each of them against the lossless file or something else) can be subject to some bias, if you know which of the lossy files you're testing.
You might have a preference for one lossy format or encoder and so you might (subconsciously) do the tests differently.

There's a way to eliminate this potential bias, by randomly renaming the lossy files.
Of course, at the end, you also need to know which file is which.
For this purpose, I found a simple script (Windows) that does just that: http://www.howtogeek.com/57661/stupid-geek...in-a-directory/
Put some files into the folder with the script, run the script and you will get: renamed files + a txt file that tells you which file is which, so you can check when you're finished.

To then use those files, it helps if they're of the same size/duration/metadata (easier with simple CBR files like WAV), so that Explorer (or whatever file manager you're using) doesn't give you any hints.
Even with different file sizes, you can select the icon view in Explorer, so that unless you hover over a file for a second or two, you won't see the details. You can then Ctrl+A on the files, unselect the ones you don't need and add the selected ones to Foobar without getting any extra information. You'll see what I mean when you try it in practice.


I found this an effective way to randomize files for blind testing on your own.
But if there's an easier way, let me know.

There's at least one thing that would improve this, though: copy the randomized files to clipboard. This would eliminate the need to select the files carefully, since they could simply be pasted into Foobar. Is there a way to add this to the script?
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greynol
post Dec 28 2012, 19:33
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To the best of my recollection I know of no issues raised about being biased based on knowing what was being tested...until now. ABC/HR and ABX already take care of that as you were already told. You were also either directly or indirectly told that ABX should not be lossy vs. lossy by at least two of us.

My point is that your needs can be met with ABC/HR better than with ABX. This is even taking each and every one of your "concerns" into account. This includes one being less transparent than another. smile.gif

I personally don't see any problems with your trying to reinvent the wheel other than you are trying to reinvent the wheel. wink.gif

If it makes any difference I've tested near-transparent (read: transparent to untrained ears) codecs professionally. The style of test used: MUSHRA not ABX. IME, the best way to bias/unbiased/train/inform yourself is to work on a codec at a time varying bitrates on various samples. Research the codecs to find thier weaknesses in order to choose the best samples to hone in most efficiently. Otherwise let ignorance be bliss.

This post has been edited by greynol: Dec 28 2012, 20:33


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