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loristrck

Welcome to the loristrck documentation!

loristrck is a cython wrapper for the C++ library Loris.

Quick Introduction

import loristrck as lt

# Read a soundfile as a numpy array
samples, sr = lt.sndreadmono("voice.wav")

# Analyze the soundfile with a frequency resolution of 30 Hz and 
# a window size of 40 Hz. A hoptime of 1/120 will result in 4x overlap
partials = lt.analyze(samples, sr, resolution=30, windowsize=40, 
                      hoptime=1/120)

# partials is a python list of numpy arrays
# select a subset of most significant partials
selected, noise = lt.select(partials, mindur=0.02, maxfreq=12000, 
                            minamp=-60, minbp=2)


# now resynthesize both parts separately 
lt.partials_render(selected, outfile="selected.wav")
lt.partials_render(noise, outfile="residual.wav")

# Save the analysis as a .sdif file with RBEP format
lt.write_sdif(partials, "analysis.sdif")

selected.wav

residual.wav

Partials can be plotted:

# plot selected partials
lt.plot_partials(selected)
lt.plot_partials(noise)

Partials are 2D numpy arrays of shape (num. rows, 5), where each row represents a breakpoint and each breakpoint consists of five values: time, frequency, amplitude, phase, bandwidth. Since partials are numpy arrays, they can be easily modified in python. For example, it is possible to stretch the timing:

def stretch(partial, factor):
    partial2 = partial.copy()
    partial2[:,0] = partial[:,0]*factor
    return partial2

stretched_partials = [stretch(partial, 20) for partial in selected]
lt.partials_render(selected, outfile="stretched.wav")

Installation

pip install loristrck

Optional Dependencies: libsndfile

In some platforms it might be needed to install libsndfile in order to load soundfiles other than wav files.

  • macOS: install via brew: brew install libsndfile
  • linux (ubuntu): sudo apt-get install libsndfile

Windows does not need any installation since the library is included in the python package (see https://github.com/pukkapies/PySoundFile)