[PD] Seam carving audio

Chris McCormick chris at mccormick.cx
Tue Jul 8 15:58:32 CEST 2008

On Tue, Jul 08, 2008 at 02:53:56AM -0400, Mathieu Bouchard wrote:
> 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?
> 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.

Yes, that is the exact point of seam carving. I'm not sure why you're
putting a negative lumps-under-the-carpet slant on the idea.

> When applying the technique to the spectrogram of a song, you should hear 
> it many times more than you'd see it.

I take it this is speculation. I am interested to know if anyone has
tried it and listened to the results.

> 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.

Isn't part of what makes a note perceptible it's higher energy compared
to the surrounding space in the spectrogram? If this is the case, seam
carving would delete seams around the notes since they have less energy,
whilst preserving the sounds of the notes themselves. This might sound
like a mess, but I'd like to hear it.

Maybe I sould just do it.



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