view README @ 33:c7d41e60930d v1.0

No, I think let's officially call it Stereo Plan here

Azi - Stereo Plan Vamp Plugin
=============================

This Vamp audio analysis plugin produces an azimuth-based stereo plan
decomposition of its input, which is expected to represent a stereo
signal in two channels of audio.

For each time increment, a vector of values is returned that divides
the stereo image into bins from left (first bin) to right (last
bin). The value in each bin corresponds, very simplistically, to the
proportion of signal energy found at that point in the stereo image at
each moment.
        
The plugin works by transforming the channel inputs into the frequency
domain using a short-time Fourier transform and then, for each
frequency, using the relative levels of the two channels at that
frequency to determine where on the stereo image the frequency can be
said to be placed. The returned vector is then a histogram of these
locations, for each time increment.
      
This is a bit experimental and perhaps should not be taken too
literally. The frequency decomposition is arbitrary into unrelated
bins without any perceptual basis and there are artifacts due to
windowing. Nonetheless, when plotted it can show some of the results
of production or recording decisions. A mono recording will appear as
a simple straight line down the middle, while recordings with limited
numbers of sources placed by "pan pot" will show separate strands for
each.