tag:help.beatunes.com,2009-07-24:/discussions/questions/70-different-resultsbeaTunes: Discussion 2011-04-07T12:31:41Ztag:help.beatunes.com,2009-07-24:Comment/21009452010-06-28T20:10:51Z2010-06-28T20:10:53ZDifferent results<div><p>Hi,</p>
<p>I analysed a same playlist with the same settings on two
different computers and the result was different.<br>
Look at these two screenshots. Some tracks don't have the same key.
And colors are differents (So if I want to sort my playlist by
color, I don't have the same order)</p>
<p>Can you tell me why ?</p>
<p>Thank you,<br>
Adau.</p></div>Adautag:help.beatunes.com,2009-07-24:Comment/21009452010-06-29T07:19:24Z2010-06-29T07:19:24ZDifferent results<div><p>Hi,</p>
<p>The color differences are easily explained, as colors are
collection specific. I.e. unless you analyzed the same songs (not
more and not less) of your whole collection, the colors will be
different guaranteed.</p>
<p>Two technical details can also lead to differences:</p>
<ul>
<li>On OSX beaTunes uses CoreAudio, on Windows it uses
QuickTime</li>
<li>On OSX beaTunes uses the Fourier transform provided by the
Accelerate framework to take advantage of whatever Apple engineers
managed to tweak out of the CPU. On Windows a straight forward FFT
is used.</li>
</ul>
<p>I was able to reproduce the differences with some songs and will
try to figure out what the exact source of it is.</p>
<p>-hendrik</p></div>hendriktag:help.beatunes.com,2009-07-24:Comment/21009452010-06-29T09:31:21Z2010-06-29T09:31:21ZDifferent results<div><p>Hi,</p>
<p>I did some digging and apparently QuickTime tends to report
different track durations than CoreAudio or even QTKit. This is
relevant, because for (e.g.) key detection beaTunes skips the first
quarter of a song before it actually analyses any data. That way it
can ignore the first couple of meaningless beats that usually come
first in a song. Now, if the length is reported differently, it
jumps to a different position in the file, which can lead to
different results - especially when the algorithm is "torn" between
two different keys.</p>
<p>I've asked Apple how to work around this, but I don't expect a
useful answer.</p>
<p>-hendrik</p></div>hendrik