ECMC PVC example file plainpv6
ECMC pvc example "plainpv6," which illustrates use of time
varying functions applied to both pitch and spectral warp index,
is a mix of two soundfiles, each with one tone, created
by the following two example scripts:
(1) plainpv6-1, in which the source soundfile is
     aiffinput=/sflib/wind/oboe.d4
and
(2) plainpv6-2 , in which the source soundfile was
     aiffinput=/sflib/perc/tamb.shake
To display one of these two script files, type
    pvcex plainpv6-1    or    pvcex  plainpv6-2
 - - - -
First note (oboe tone), created by script "plainpv6-1" :
Here are the parameters that differ from the defaults:

(1) input soundfile:
aiffinput=/sflib/wind/oboe.d4  

(2) gen functions
Two functions are created, the first to control spectral warp index,
the second to control pitch:
# gen3 -Llength v1 v2 ... vN
 gen3 -L1000 5 5 -5 -5 5 > $SFDIR/spectrumfunc
#   gen4 generates exponenetial segments; "a" values determine shape &
#  depth of curve: 0 = linear, neg. = exponential, pos. = inverse expo.
# gen4 -Llength t1 v1 a1 ... tN vN
 gen4 -L1000 0 -2 1 \
.25 -2 1 \
.5 4 1 \
.8 4 1 \
1 2 > $SFDIR/pitchfunc

(3) time warping: the duration of the input soundfile is stretched
by 50 % :
time_expansion_contraction_factor=1.5

(4) Time varying changes in the spectral warping are produced by
the spectrum warpshape function. At the beginning & end of the
note the wewaker partials are attenuated, "simplifying" the timbre.
In the middle of the note, the weaker (higher) partials are boosted
in intensity, creating a "brighter," more nasal timbre:

spectrum_warpshape_index=$SFDIR/spectrumfunc   # int, float or FUNC

(4) The output pitch begins a major second below the original pitch,
glisses up to a major third higher than the original pitch, then
at the end of the note gliss down, ending a major second higher
than the original pitch:
pitch_transposition_in_semitones=$SFDIR/pitchfunc  # int, float or FUNC

pitch_transposition_in_semitones=$SFDIR/pitchfunc  # int, float or FUNC
(5) EQ is applied. Freqencies between 500 and 1200 herz are eliminated:
FILTER_TYPE__0_bandpass__1_bandreject=1
BRICKWALL_FILTER_window_low_frequency=500
BRICKWALL_FILTER_window_high_frequency=1200

----
Second "note" (the tambouring shake), produced by example script
file "plainpv6-2:"
All of the changes above are applied to sflib/perc/tamb.shake.
File "plainpv6-2" is identical to file "plainpv6-1" except
for the difference in input sound. Also, the output gain was
modified in example "plainpv6-2" like this:
  gain_in_decibels=-6   # in dB, int, float or FUNC
to eliminate clipping by about 6 dB.
-----
At the end of both scripts the line
   rm $SFDIR/spectrumfunc $SFDIR/pitchfunc
is included to delete the two function files.
 -  -  - 
To see the source files for "plainpv6-1" or "plainpv6-2" type
   pvcex  plainpv6-1    or else      getex plainpv6-1
   pvcex  plainpv6-2    or else      getex plainpv6-2