Please explain waveform~'s behavior


    Dec 29 2006 | 9:05 pm
    I just noticed that when selecting all in a waveform~ the end point of the selection is not the total length of the buffer~. I am pretty sure I've noticed that with very short files this difference is larger than with very long files (which seems counterintuitive if this were a "feature"). I've been searching the docs and archives but don't see any previous mention of this behavior.
    This is throwing off some calculations in a patch when pitch scaling with gizmo~ so that different length buffers~ can playback at the same speeds but at their original pitches without FFT time stretch - however the error is too small for my human ears to notice so it's not really a huge deal and if it were I could work around it with info~.
    That being said, I am curious why this is the case and/or if I should report it as a bug (using the proper guidelines of course). Here is a demonstration:
    max v2;

    • Dec 29 2006 | 10:34 pm
      i can confirm, but i dont think it is a bug.
      there is a difference of approximatively 1 sample with 2second long files.
      under 1 sample for a three minute long file.
      around 2 samples for 170ms long files.
      it might have to do with the "pixel to ms" conversion/accuracy ?
      Quote: Lewis wrote on Fri, 29 December 2006 13:05
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      > I just noticed that when selecting all in a waveform~ the end point of the selection is not the total length of the buffer~. I am pretty sure I've noticed that with very short files this difference is larger than with very long files (which seems counterintuitive if this were a "feature"). I've been searching the docs and archives but don't see any previous mention of this behavior.
      >
      > This is throwing off some calculations in a patch when pitch scaling with gizmo~ so that different length buffers~ can playback at the same speeds but at their original pitches without FFT time stretch - however the error is too small for my human ears to notice so it's not really a huge deal and if it were I could work around it with info~.
      >
      > That being said, I am curious why this is the case and/or if I should report it as a bug (using the proper guidelines of course). Here is a demonstration:
      >
    • Dec 29 2006 | 11:25 pm
      I was thinking about this as well, but shouldn't different size waveform~s (displayed size on the screen) give different size "errors"? I tried resizing and the error stays the same (I've not tried a different screen resolution though).
      Quote: (karrrlo) wrote on Fri, 29 December 2006 14:34
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      > it might have to do with the "pixel to ms" conversion/accuracy ?
      >
      ----------------------------------------------------
    • Jan 02 2007 | 2:02 am
      i know i tried that as well.
      one should check if the same problem happens when zooming in or out of the waveform~.
      hopefully somebody wil come up with better answers then me ;)
      best,
      Quote: Lewis wrote on Fri, 29 December 2006 15:25
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      > I was thinking about this as well, but shouldn't different size waveform~s (displayed size on the screen) give different size "errors"? I tried resizing and the error stays the same (I've not tried a different screen resolution though).
      >
      > Quote: (karrrlo) wrote on Fri, 29 December 2006 14:34
      > ----------------------------------------------------
      > > it might have to do with the "pixel to ms" conversion/accuracy ?
      > >
      > ----------------------------------------------------
      >
      >
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