 ECMC PVC soundfile example >> /sflib/x/twarp6 << :
Soundfile /sflib/x/twarp6 mixes 5 source soundfiles together in succession
    twarp6-1, twarp6-2, twarp6-3, twarp6-4 and  twarp6-5
in order to illustrate some applications of time point dithering, or random
deviations introduced in reading an analysis file. This can be used for
many purposes :  sometimes slight dithering can eliminate artifacts or
an "artificial" quality when time stretching a sound. It can also be
used for phasing/flanging effects, for granularization of a sound (slicing
and dicing it into fragments), to alter the tempo, and for other creative
purposes.
In /sflib/x/twarp6, the 5 source soundfiles (twarp6-1 through twarp6-5),
each 4.39 seconds in duration, are separated by temple block hits so that
you can more easily distinguish the starting points of these source soundfiles.
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Example /sflib/x/twarp6-1, heard first in twarp6, contains no dithering,
but rather acts as a reference or "source" for the subsequent alterations.
 The analysis file used is voicetest.clip, created by ECMC examples file
 pvanalysis.voicetest
 The output duration is increased to 4.38 seconds
 duration=4.38      # MUST BE CHANGED to desired output resynthesis duration

  Reading of the analysis file:
  Autostop is turned OFF so that when we reach the end ofthe analysis file 
 twarp will loop beack to the beginning of the analysis and resynthesis will
 continue
  autostop_on_1__off_0=0 # AUTOSTOP IS TURNED OFF TO ENABLE LOOPING

 In contrast to earlier twarp examples, "rate" mode rather than
 "explicit" mode is used to control the rate at which the analysis is read:
 DATA_access_mode__explicit_0__rate_1=1  # 0 = explicit, 1 = rate

 Reading of the analysis file begins half way through the file and the
 speed is raised by 1/3
 time_point=.5   # int, float or FUNC
 rate_multiplier=1.33

 Within the 4.38 second output duration the analysis loops 3 and a half times

 Finally , a gen function file controls the pitch, which begins 3 semitones
 lower than the original, glissandos up to 4 semitones higher than the
 original, then slides down to 1 semitone above the original:
 gen1 -L1000 0 -3 .6 4. 1. 1.  > $SFDIR/pitchfunc
 pitch_transposition_in_semitones=$SFDIR/pitchfunc   # int, float or FUNC

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The other 3 examples (twarp6-2 through twarp6-5) heard in succession within
/sflib/x/twarp6 are identical to example twarp6-1 (the first note) in every
way except that different types of dithering are applied.

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In example twarp6-2 (the second note) slight dithering (random jitter) is
introduced in reading the analysis file.
Every 8 milliseconds (.008) the reading of the analysis varies randomly
by an amount somewhere in between + or - 25 milliseconds (.025)

  timepoint_dither_window_in_seconds=.025 # 
  time_point_change_response_time_in_seconds=.008 # 

These small values  introduce hesitations and random (though brief, and rather
subtle) increases  and  decreases in tempo (accerlandi and rallendtandi)

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In example twarp6-3 (the third note) rapid, wide dithering is used.
The reading of the analysis can vary by _/- a half second, and is varied
 every 50 milliseconds:
 timepoint_dither_window_in_seconds=.5 
 time_point_change_response_time_in_seconds=.05

 The result of this rapid, fairly wide skipping around within the analysis file
 is granualarization of the original sound. Higer frequencies also tend to
 be exaggerated. (If we don't want this, we could adjust the  two
 HIGH_SHELF_EQ parameters, reducing these higher frequencies
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In example twarp6-4 (the fourth note) illustrates slow dithering:
   timepoint_dither_window_in_seconds=.05 
   time_point_change_response_time_in_seconds=.2
 Every .2 seconds the time point withinthe analysis file is varied randomly
 by a value somewhere between +/- .05 seconds. The result is rather surprising,
 slowing down the tempo .

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Example twarp6-5 (the fifth note) is similar to twarp6-4 but the dithering
is more extreme:
 timepoint_dither_window_in_seconds=.2 
 time_point_change_response_time_in_seconds=.5 

 The result is much "hesitation," "hesitation" and "stuttering"
 With all of this back-and-forth jitter, only a portion of the analysis file
 is read within the 4.38 second output duration

