Although not quite as successful as STRETCH,
this works nicely on large shrink factors (.1-.2)
as it throws out lots of data without bothering
to analyze it first. The quality is somewhat less
good than from the original pv set with conservative
parameters, but the run time is very much faster. 

shrink:  frequency interpolated time compression
shrink   [flags] < floatsams > floatsams
        R:      sampling rate [44100]
        N:      fft length [2048]
        M:      window size in samples [16384]
        D:      decimation factor in samples [2048]
        I:      interpolation factor in samples [2048]
        P:      oscillator bank pitch factor [0.0]
        S:      shrink factor [.5]
        t:      oscillator resynthesis gate threshold [0.0]

S - value of .5 cuts duration in half, without
changing pitch. I'm not sure what happens
for S > .5 - there's no particular reason
to expect the processor to work under those
conditions.
