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TITLE:: FluidSines
SUMMARY:: Sinusoidal Modelling and Resynthesis
CATEGORIES:: Libraries>FluidDecomposition
RELATED:: Guides/FluCoMa, Guides/FluidDecomposition
DESCRIPTION::
This class applies a Sinusoidal Modelling process on its audio input. It implements a mix and match algorithms taken from classic papers. It is part of the Fluid Decomposition Toolkit of the FluCoMa project. footnote:: This was made possible thanks to the FluCoMa project ( http://www.flucoma.org/ ) funded by the European Research Council ( https://erc.europa.eu/ ) under the European Unions Horizon 2020 research and innovation programme (grant agreement No 725899).::
The algorithm will take an audio in, and will divide it in two parts: LIST::
## a reconstruction of what it detects as sinusoidal;
## a residual derived from the previous signal to allow null-summing::
The whole process is based on the assumption that signal is made of pitched steady components that have a long-enough duration and are periodic enough to be perceived as such, that can be tracked, resynthesised and removed from the original, leaving behind what is considered as non-pitched, noisy, and/or transient. It first tracks the peaks, then checks if they are the continuation of a peak in previous spectral frames, by assigning them a track. More information on this model, and on how it links to musicianly thinking, are availabe in LINK::Guides/FluCoMa:: overview file.
CLASSMETHODS::
METHOD:: ar
The audio rate version of the object.
ARGUMENT:: in
The input to be processed
ARGUMENT:: bandwidth
The width in bins of the fragment of the fft window that is considered a normal deviation for a potential continuous sinusoidal track. It has an effect on CPU cost: the widest is more accurate but more computationally expensive.
ARGUMENT:: thresh
The normalised threshold, between 0 an 1, to consider a peak as a sinusoidal component from the normalized cross-correlation.
ARGUMENT:: minTrackLen
The minimum duration, in spectral frames, for a sinusoidal track to be accepted as a partial. It allows to remove space-monkeys, but is more CPU intensive and might reject quick pitch material.
ARGUMENT:: magWeight
The weight of the magnitude proximity of a peak when trying to associate it to an existing track (relative to freqWeight - suggested between 0 to 1)
ARGUMENT:: freqWeight
The weight of the frequency proximity of a peak when trying to associate it to an existing track (relative to magWeight - suggested between 0 to 1)
ARGUMENT:: winSize
The window size. As sinusoidal estimation relies on spectral frames, we need to decide what precision we give it spectrally and temporally, in line with Gabor Uncertainty principles. http://www.subsurfwiki.org/wiki/Gabor_uncertainty
ARGUMENT:: hopSize
The window hope size. As sinusoidal estimation relies on spectral frames, we need to move the window forward. It can be any size but low overlap will create audible artefacts.
ARGUMENT:: fftSize
The inner FFT/IFFT size. It should be at least 4 samples long, at least the size of the window, and a power of 2. Making it larger allows an oversampling of the spectral precision.
RETURNS::
An array of two audio streams: [0] is the harmonic part extracted, [1] is the rest. The latency between the input and the output is (( hopSize * minTrackLen) + windowSize) samples.
EXAMPLES::
CODE::
// load some audio to play
b = Buffer.read(s,File.realpath(FluidSines.class.filenameSymbol).dirname.replace("Classes","AudioFiles/Tremblay-AaS-SynthTwoVoices-M.wav"));
// run with basic parameters - left is sinusoidal model, right is residual
{FluidSines.ar(PlayBuf.ar(1,b.bufnum,loop:1))}.play
// interactive parameters with a narrower bandwidth
{FluidSines.ar(PlayBuf.ar(1,b.bufnum,loop:1),30,MouseX.kr(),5)}.play
// null test (the process add a latency of (( hopSize * minTrackLen) + windowSize) samples
{var sig = PlayBuf.ar(1,b.bufnum,loop:1); [FluidSines.ar(sig).sum - DelayN.ar(sig, 1, ((( 512 * 15) + 2048)/ s.sampleRate))]}.play
::