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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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Brand
post Dec 27 2012, 11:30
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As AndyH-ha explained, this is for doing several separate ABX tests.

Just a quick practical example: you want to determine which is (more) transparent at 150kbps, MP3 or Vorbis. So you do an ABX test with the MP3 against the lossless and then another ABX test with Vorbis against the lossless.
If you know whether you're ABXing MP3 or Vorbis, you could be (subconsciously) biased and perform the tests differently. Randomly renaming the files first prevents you from knowing this.
(It would make sense to convert the MP3 and Vorbis to WAV before randomizing.)


Randomly renaming the files could also be used for simply playing back the files on their own (no ABX) to subjectively evaluate which file 'sounds better'.
ABC/HR mentioned above is more sophisticated for this kind of task, but it requires a dedicated tool or an external tester.

This post has been edited by Brand: Dec 27 2012, 11:40
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