On Mon, 9 Jun 2008, Chris McCormick wrote:
Something struck me whilst out walking today; has anyone applied the seam carving technique: http://en.wikipedia.org/wiki/Seam_carving <www.youtube.com/watch?v=6NcIJXTlugc> to FFT data to do a timestretch/timecompress that is more sensitive to attack sounds and note lengths?
I doubt that this would work at all. It's already of dubious use on images, as it introduces distorsions that even though they are made to look least like distorsions, are serious distorsions anyway, and can mess up the perception of the content seriously. Compared to the "deleting least important columns" technique that they show at 1:40, the Seam Carving technique sweeps the distorsions under the carpet. After that, don't wonder what the big lump under the carpet is.
When applying the technique to the spectrogram of a song, you should hear it many times more than you'd see it.
Perhaps it can be used as an interesting special effect, supposing that what you want to do is mess up the rhythm seriously and turn chords into arpeggios in truly weird ways. However, it will work at the sine wave level, which is somewhat less attractive than if it worked on notes.
Instead of applying it on FFT, you could apply it on a piano roll. (A real one, unlike GridFlow's patch of that name, which is actually botched FFT synthesis)
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