06-table-stutter.py - Variable length table reading.¶
This little program use a function and a time-variable function caller to stutter a sound loaded in a table. The starting point of the table playback is set initially to near the end of the table, and move toward the beginning each time a new playback is called.
For the playback, we use a Pointer object, which is a table reader with control on the pointer position (normalized between 0 and 1).
from pyo import * import random s = Server().boot() STUTTER = 0.025 # Delta time added each time the playback restart. FADETIME = 0.01 # Fadein-fadeout time to avoid clicks. # Load a sound in the table and get its duration. table = SndTable(SNDS_PATH + "/transparent.aif") tabdur = table.getDur() # Intialize the line used to read the table. line = Linseg([(0, 0), (1, 1)]) # Amplitude envelope, to avoid clicks. amp = Fader(FADETIME, FADETIME, dur=STUTTER, mul=0.5) amp.setExp(2) # Read the sound and mix it to stereo. read = Pointer(table=table, index=line, mul=amp).mix(2).out() # Global variables (start position and playback duration). start = tabdur - STUTTER dur = STUTTER def go(): "Read a segment of a sound table and set the duration before the next iteration." global start, dur # Create the pointer segment (from normalized start position to the end of the table) line.list = [(0, start / tabdur), (dur, 1)] # Assign duration to the envelope and the function caller (Pattern). amp.dur = pat.time = dur # Decrement start position and increment duration by STUTTER seconds. start -= STUTTER dur += STUTTER # Reset start and dur variables when reaching the beginning of the sound. if start < 0: start = tabdur - STUTTER dur = STUTTER # Activate the pointer's index line and the amplitude envelope. line.play() amp.play() # Call go() each time the playback reaches the end of the file pat = Pattern(function=go, time=STUTTER).play() s.gui(locals())