User-Defined Opcode Database



This is a repository of User-Defined Opcodes for the Csound music synthesis software. User-Defined Opcodes are opcodes for Csound created using Csound orchestra text. More information about how to create a User-Defined Opcode can be found here.  This database was edited by Steven Yi.

Signal Generators

ADSD - An envelope generator modelling the classic analogue ADSD envelopes
BufFiPl1 - Plays a mono sample from a GEN01 function table, including sample rate conversion
BufFiPl2 - Plays a stereo sample from two GEN01 function tables, including sample rate conversion
BufFiPl4 - Plays a four channel sample from four GEN01 function tables, including sample rate conversion
BufFiPl8 - Plays an eight channel sample from eight GEN01 function tables, including sample rate conversion
BufPlay1 - Plays audio from a mono buffer (function table), with different options
BufPlay2 - Plays audio from a stereo buffer (two function tables), with different options
FilePlay1 - Plays a mono signal from a mono or stereo soundfile
FilePlay2 - Plays a stereo signal from a mono or stereo soundfile
footarray - Interface for a foot array which outputs program change MIDI messages. Can be used with any MIDI program change capable device.
GaussTrig - Outputs a-rate impulses around a certain frequency.
Linek - performs a linear interpolation from one value to another value in a certain time whenever a trigger is received
LpPhsr - creates a time pointer for loops
msrOsc - Simple Generator
p5glove - Unit generator for P5 data glove
PartikkelSimpA - A simplified version of the Partikkel opcode, but with some additional parameters
PartikkelSimpB - The same as PartikkelSimpA, but with a time pointer input
pgmin - Read program change messages from MIDI input
RandomWalkA - Generate random walk at a-rate
RandomWalkK - Generate random walk at k-rate
rbatonPercPad - Senses trigger/whack strength as well as X and Y coordinates of the two batons in a Max Mathew’s Radio Baton system
rbatonPot - Implements a sensor for the 4 pots, 2 footswitches and B15+ button on the Max Mathew’s Radio Baton unit
rbatonXYZ - polls X, Y, and Z coordinates of a Max Mathew’s Radio Baton
stereoGrain - Granular synthesis similar to granule but in stereo with control rate parameters and unlimited transpositions
TransGen - Transient envelope generator, pulse divider, and/or LFO.
vowgen - fof-based vocal generator with morfable vowels

Signal Modifiers

~ Effects ~
Baboon - UDO wrapper for the babo opcode
decimator - Sample rate / Bit depth reduce. Based on the work of Steven Cook ( k-rate parameters)
ensembleChorus - A stereo chorus opcode with multiple voices
freqShift - Detunes an audio signal
PitchShifter - Delay-line pitchshifter
SCReverb - 8 delay line stereo FDN reverb
SigRec - A table-based signal recorder (looping sampler), with pitch control
SigReverse - A table-based reversing opcode
trackerSplice - signal splicer
~ Filters ~
Fofilter - A formant filter version of the FOF opcode
Moogladder - An improved implementation of the Moog ladder filter
Statevar - A digital version of the analogue state variable filter
tap_tubewarmth - tap_tubewarmth – A port of Tom Szilagyi’s TAP TubeWarmth LADSPA plugin to a Csound User-Defined Opcode
Vocoder - channel vocoder with user-specified number of bands
vowel - vowel filter with morfable vowels
~ Panning and Spatialization ~

bformatQuad - Converts quadrophonic to b-format
bformatStereo - Converts stereo to b-format ambisonics
circumspect - redistribute the spectral content of a monaural signal between 6 loudspeakers - pans stereo input to stereo output
pan_delay_and_filtered - Pan using delay and filters
pan_equal_power - Equal Power Panning
pan_gm2 - Equal Power Panning scheme defined by MIDI Association for GM2 in RP-036
pan_simple - Simple Linear Pan
pan_sin - Pan using Sin/Cos to create more even power between channels
pan_sqrt - sqrt method for panning
quadBformat - Converts b-format to quadrophonic
stereoAsymmetry - Side-only panning of a stereo signal
stereoBalance - Stereo ‘panning’ using the balance technique
stereoBformat - Converts b-format ambisonics to uhj stereo
stereoMpan - Middle panorama panning of the ‘M’ component of a stereo signal
stereoMS - Converts Stereo to MS and MS to Stereo
stereoRotate - Stereo ‘panning’ using the middle-side technique
stereoWidth - Changes the image width of a stereo signal


ampdbN - Normalized conversion from db to amplitude
ampSlider - Converts a scaled (0-1) value to a value resembling a hardware mixer slider
BufCt1 - creates a function table of ilen seconds for recording
BufCt2 - creates two function tables of ilen seconds for recording
BufFiCt1 - creates a gen01 function table from a mono soundfile
BufFiCt2 - creates two gen01 function table from a stereo soundfile
BufFiCt4 - creates fout gen01 function table from a four channel soundfile
BufFiCt8 - creates eight gen01 function table from an eight channel soundfile
BufFiCtNd1 - creates a non deferred function table from a mono soundfile and returns its length
BufFiCtNd2 - creates two non deferred function tables from a stereo soundfile and returns the length
BufRec1 - Records in a mono buffer (function table)
BufRec2 - Records in a stereo buffer (= two function tables)
Counter - Step counter
declick - removes clicks from signal start and end
deflutter - deflutter k-rate input (data smoothing)
ExpCurve - Normalised exponential curve with variable steepness
F2M - Comverts a frequency to the next possible MIDI note number
F2MC - converts a frequency to a MIDI.Cent note number
FilDir - Returns the directory in a given path
FilDirUp - Returns the directory above the current directory
FileToPvsBuf - Writes an audio file to a pvs buffer
FilNam - Returns the file name in a given path
FilSuf - Returns the suffix of a filename or path, optional in lower case
findPowerOfTwo - Given a value in seconds, finds a power of two size equal to or greater than it in samples
flip - Flips an incoming floating point value at k-rate
FracLen - Returns the real length of the fractional part of a number
FreqByCentTab - frequency calculation of a step of a scale which is defined by a list of cent values
FreqByEqScale - frequency calculation for one step of an equal tempered scale
FreqByRatioTab - frequency calculation of a step of a scale which is defined by a list of proportions
ftreverse - reverses an ftable’s contents in place at k-rate
gainslider - Logarithmic gain slider
getFrequency - Returns frequency whether being passed in pch or frequency
hysteresis - Implements classic 2-threshold hysteresis. Useful for performance controllers
KeyOnce - Returns ’1′ once if a certain key has been pressed or released
KeyStay - Returns ’1′ as long as a certain key is hold
LogCurve - Normalised logarithmic curve with variable steepness
lowpass - A k-rate smoothing UDO that is useful for averaging performance controller data
midiMonitor - Displays midi channel and control number information
MS2S - Converts a floating point number in the format min.sec to seconds
PfieldsToTable - Transfers score parameter fields to a function table
PhsEdge - Reports whether the upper or lower border of a phasor has been reached
Print_a - Prints an audio signal (vector) every kPeriod seconds
Residual - extracts stochastic components (transients etc) from a sound (using csound 5 opcodes)
Scala - Scales an incoming a-signal from a certain range to another range
scale - Scales incoming value to user-definable range. Similar to scale object found in popular dataflow languages
Scali - Scales an incoming i-variable from a certain range to another range
Scalk - Scales an incoming k-signal from a certain range to another range
SinesToSSTI - returns a function table with one of the four standard waveforms, produced by the addition of harmonics
Stayed - Reports if a control signal has stayed at the same value for a certain time
StrayElMem - Tests whether a string is contained as an element in an array-string
StrayGetEl - Gets one element from a string-array
StrayGetNum - Gets one number from a string-array
StrayLen - Returns the length of an array-string
StrayNumLen - Returns the length of numerical elements in an array-string
StrayNumMem - Tests whether a number is a member of an array-string
StrayNumSum - Adds the elements in a numerical array-string
StrayNumToFt - Converts a string-array which just consists of numbers or simple math expressions to a function table
StrayRemDup - Removes duplicates in an array-string
StrayRev - Reverses the elements of an array-string
StraySetEl - Inserts an element in an array-string at a certain position
StraySetNum - Inserts a number in an array-string at a certain position
StraySub - Returns a subset of elements in an array-string
StrExpr1 - Calculates a simple binary expression in a string and returns the result as a number
StrExpr2 - Calculates a binary numerical expression in a string and returns the result as a number. One of the elements can be itself a binary expression, in which case it must be set in parentheses. Requires the UDO StrExpr1
StrNumP - tests whether a string is a numerical string
TbDmp - Prints a function table at i-time
TbDmpk - Prints a function table at k-time
TbDmpS - Prints a table with an introducing string at i-time
TbDmpSk - Prints a table with an introducing string at k-time
TbMem - Looks whether a number is in a function table
TbPrmRnd - Permutes the values of a function table randomly, at i-time
TbPrmRndk - Permutes the values of a function table randomly, at k-time
TbRmDp - Removes duplicates from a function table
TbToLin - Reads a table in the same way as a linseg opcode
TbToSF - writes the content of a table to a soundfile
tieStatus - Returns the status of a note in a group of tied notes
Tuner - Tunes a given fundamental to a user-provided scale
Y_x4p_i - Calculates a Y value from a given X and 2 pairs of X/Y points, at init-time
Y_x4p_k - Calculates a Y value from a given X and 2 pairs of X/Y points, at k-time


boomerangPointer - Pointer to read a function table forwards then backwards or vice versa
filterBank - Defines a bank of bandpass filters in parallel whose outputs can be scaled using a function table
linearPointer - Pointer to read a function table linearly, forwards or backwards
pvshift - Pitch shifting and spectral stretching with pvs streams
RecursiveDiskin - Alters kpitch and iskiptime each time it calls itself to create a little bit of texture
sampleSlicer - Reads a function table in incremental slices
sittinginaroom - A simple,recursive opcode that has pleasant effects. The name pretty much describes what it does.