quality transient analysis

    Matthew Aidekman
    Mar 12 2006 | 12:34 am
    END GOAL------------------------------------------------- A program which takes a soundfile.wav, and produces a soundfile.xml in the same directory. the xml file would have tons of useful metadata just waiting to be indexed and searched.
    WHATS WRONG---------------------------------------------- it seems my detecting of transients and pitches are wavering around in terms of latency. (15-40 ms) I'm using bonk~ and analyzer~. but I can't measure the latency. Also, if my attack happens to be at time zero bonk~ doesn't see it.
    I'm hoping to generate protools' beat detective quality information. maybe this project is over my head.... sob....
    Can any know-it-alls advise me on generating quality transient maps? (in or out of realtime) vector sizes? window shapes? magic objects?
    -matt
    this is an example of how I'm trying it now.
    • Jean-Francois Charles
      Mar 12 2006 | 2:29 pm
    • Matthew Aidekman
      Mar 12 2006 | 4:50 pm
      wow this is so helpful and I am so silly for not seeing it. bonk~ uses FFT as well.
      maybe what I'll do is use the fft objects for quantity and approximate positions of attacks, then focus on those areas and look for attacks in the time domain.
      Nonlinearity rocks!
      I'll post an example if I get it. -matt
      . . . . . . . . . . . . Http://www.EstateSound.com Http://ideasforstuff.blogspot.com . . . . . . . . . . . .
    • Peter McCulloch
      Mar 12 2006 | 7:01 pm
      If you're doing off-line analysis, you could use a delay~ equal to the FFT size (or possibly 2X to account for overlap?)
      For quick and dirty approaches, you might try an envelope follower on a highpass filter. (and looking at thresholds on that)
      You also might get something out of zerox~ in combination with an envelope follower. (multiply the output of the env follower by the zerox~ sig?) That way it ignores the high values produced by zerox~ produced when nobody is playing.
      Peter McCulloch