PartikkelExplorer

Oeyvind Brandtsegg, 2007

obrandts@gmail.com

PartikkelExplorer is a python gui for experimenting with the csound partikkel opcode.

This document contains a few references to the code, should you need to make changes to the application.

However, it should be possible for inexperienced users to just have a go at experimenting with partikkel as it is.

Selecting an audio output device:

Graphical editing windows:

Selecting an audio output device:

The csound commandline parameters can be found in the file csoundCommandLine.py,

this is the only part of the code that you probably will have to edit.

For details on the csound command line parameters, refer to the csound manual.

To run:

Run the file PartikkelExplorer.py

Here's a brief introduction to what the GUI does:

Dropdown menus:

These select the audio waveforms to be used as source for grains.

To add your own samples, edit the file ftables_samples.inc,

adding your sample like this:

giZyne ftgen 0, 0, 262144, 1, "Zyne1.wav", 0, 0, 1

You will also need to write the ftable number to a csound chn string channel, so that Python can refer to the table number by name.

Like this:

chnset giZyne, "giZyne" ; makes ftable number accessible via string channel

Finally, you must add your sample name to the dropdown menu controls in the Python GUI,

this is done in line 110 of PartikkelExplorer.py:

soundlist = ['giZyne','giFlyndrSand','giVib_Eb','giVok1']

Many of the sliders correspond directly to partikkel parameters (see partikkel manual page). However, the wxPython sliders does not work with floats so I've scaled the (integer) output of the sliders where needed. See line 124 of PartikkelExplorer.py if you need to check the scaling of each parameter.

Grain Amp : The master amplitude.

Grain Rate : Number of grains per second.

GrFmIndx : Frequency modulation index, modulating the grain rate.

GrFmFqRat : Frequency modulation frequency, as percentage of the grain rate.

GrDist : Grain distribution.

GrTransp : Transposition (pitch) scaling of all grains.

SweepShape : Shape of the curve for transposition sweeps (depends on the setting of StartFreq and EndFreq in the multislider windows)

FmIndex : FM Modulation index, modulating the pitch of source waveforms.

FmFreq : Frequency of the FM oscillator, modulating the pitch of source waveforms. If Frequency is set to zero, audio feedback is used instead of an oscillator for the FM modulator signal.

GrDur : Grain duration, in percent of 1/grainrate, so e.g. a value of 400 gives a grain overlap of 4.

GrAttack: Balance between attack time and decay time for grain enveloping, 0 = zero attack time and full decay time.

GrShape: Amount of grain (attack and decay) enveloping. This can also be described as balance between enveloped time(attack+decay) and sustain level time, 0 = no time at sustain level.

GrEnv2: Amount of secondary enveloping. A secondary envelope shape can be applied to the whole grain, currently a falling sigmoid envelope is used. This can be changed by editing ftables_envelopes.inc (line 5) and/or partikkel_instr.inc (line 39). The attack and decay envelopes can be edited in a similar way.

TimLfoFq : LFO frequency, modulating the time pointer offset (see TimPosOff).

TimLfoAmt : LFO amount, modulating the time pointer offset (see TimPosOff).

TimPosOff : Time position offset, reading of source grain waveforms start from this position in the waveform. Scaled as percentage of the waveform length. For example, setting this to 50 will let new grains start reading from halfway through the source waveform. For single cycle waveforms it would make sense to call this "phase", but for sampled sounds it makes more sens to name it "time position".

RandMask : Amount of random masking (muting) of grains.

ChnWidth : Stereo spread of partikkel audio outputs 1 and 2.

d2Dly : Delay time for partikkel audio output 2, in percent of 1/grainrate.

chorusAmt : Chorus effect send amount for partikkel audio output 3.

reverbAmt : Reverb effect send amount for partikkel audio output 4.

ChnRewrit : Rewrite LFO speed. This controls a continuous rewriting of the channel masks ftable, similar to a panning LFO. Since some partikkel audio outs are used for stereo positioning and other outputs are used for effect sends, this control enables a sort of sonic animation. When setting the control to zero, the original contents of the channel mask table is restored.

TrnAmp : Amplitude for trainlets. This is implemented so that increasing trainlet amplitude automatically decreases amplitude for waveform grains. The resulting wave mix values are written to the wave mix ftable at the index currently selected in the GUI control WavMaskEdit.

TrnCps : The fundamental frequency of the trainlets.

TrnHarm : Number of harmonics for the trainlets.

TrnChrom : Trainlet chroma. Harmonic balance of the trainlets.

nFmIndx : Frequency modulation index for a noise modulator signal added to the FM modulator (FmIndex,FmFreq controls) modulating the pitch of source waveforms.

nFmDist : Random distribution for the noise FM modulator signal. See csound opcode rnd31. Gui values are scaled * 0.01.

nFmFreq : Lowpass filter frequency for the noise FM modulator signal.

Number boxes:

ChMaskStart : Start (loop start) index for reading channel mask values. Channel masks specify which audio output grains are routed to, per grain.

ChMaskEnd : End (loop end) index for reading channel mask values.

GnMaskStart : Start (loop start) index for reading gain mask values. Gain masks specify gain per grain.

GnMaskEnd : End (loop end) index for reading gain mask values.

FmMaskStart : Start (loop start) index for reading FM mask values. FM masks specify modulation index per grain.

FmMaskEnd : End (loop end) index for reading FM mask values.

Fq1MaskStart : Start (loop start) index for reading pitch sweep start values. Transposition at start of grain, per grain.

Fq1MaskEnd : End (loop end) index for reading pitch sweep start values.

Fq2MaskStart : Start (loop start) index for reading pitch sweep end values. Transposition at end of grain, per grain.

Fq2MaskEnd : End (loop end) index for reading pitch sweep end values.

WavMaskStart : Start (loop start) index for reading waveform mix values. Mix of 4 source waveforms per grain.

WavMaskEnd : End (loop end) index for reading waveform mix values.

WavMaskEdit : The current waveform mix index to edit by using the "WaveMix" (xyPlot or joystick) graphical editing window.

Graphical editing windows:

Each of these has 8 "sliders" representing indices for "per grain" control parameters. You can set values for each index by clicking or dragging with the mouse. Csound table values are updated accordingly. Loop points, e.g. deciding which of the graphically plotted values will actually be used are set by the number boxes described above.

Channel Masks : Values representing output routing per grain.

Gain Masks : Values representing gain per grain

FM Index Masks : Values representing FM modulation index per grain

Start Freq Masks : Value representing (transposition) pitch sweep start value per grain.

End Freq Masks : Value representing (transposition) pitch sweep end value per grain.

WaveMix : X and Y axis used to control the mix of 4 source waveforms per grain.