User Guide
User Guide | Transform Guide | OSW on the Web

Note: OSW must be running in order for tutorial-patch links to function properly.

Audio

audio/additive.osw

A simple harmonic additive synthesizer in which the frequency of each partial is a multiple of the fundamental. Use the sliders to increase or decrease the contribution of each partial to the overall sound.

audio/allpass_filter.osw

Demonstrates use of feed-forward and feedback comb filters to create allpass filter. This patch is intended for tutorial purposes. For real applications, use the Allpass transform.

audio/am.osw

The amplitude of a sine wave is modulated by another waveform. The user can change both the shape and frequency of the modulator. At low frequencies, the result is a tremolo effect. At higher frequencies, the modulation becomes part of the timbre of the source signal; this technique is known as ring modulation.

audio/amplifier.osw

Two methods for amplifying/attenuating a signal: the multiplication operator and the Gain transform.

audio/amp_envelope.osw

Use of the Lines transform to create a simple amplitude envelope.

audio/biquad_explore.osw

Use the sliders to change the values of the biquad coefficients and observe on the scope how the frequency response changes.

audio/calc_bandpass.osw

Calculate biquad coefficients for a 2nd order bandpass filter. This patch uses the same formula as the Bandpass transform.

audio/calc_notch.osw

Calculate biquad coefficients for a 2nd order notch filter.

audio/decaying_pulses.osw

A delay line is used to create a sequence of decaying pulses. If the delay time is short enough, then the pulses will be heard as a single sound with a fundamental pitch period (inverse of the frequency) equal to the delay time.

audio/dust.osw

This patch uses a comparison operator on a noise source to create "extremeley low-passed noise". The result sounds like scratches or dust on a vinyl record. The "dust" signal can also be used as a random-time series of pulses to excite resonators, etc.

audio/dust_demo.osw

A demo patch that uses the dust signal generator described above.

audio/echo_machine.osw

Use of a feedback delay line to create an "echo" effect.

audio/fast_convolution.osw

Using multiplication of frequency-domain spectra for fast convolution of signals.

audio/feedback_loop.osw

audio/feed_back.osw

A feedback delay line.

audio/feed_forward.osw

A feed-forward delay line.

audio/flanger1.osw

Flanger with a single comb-filter stage.

audio/flanger_demo.osw

Demo patch that incorporates flanger tutorial. For real applications requiring a flange effect, use of the fx::Flanger transform is recommended.

audio/fm.osw

A phase-modulation synthesizer, often referred to as "frequency modulation". A sinusoid called a modulator is used to alter the perceived frequency of another signal called a carrier by changing the phase input to a wavetable. The amplitude of modulator determines how much modulation is applied to the carrier, and it's frequency is set as a user-set proportion of the current carrier frequency.

audio/lfo_filter_sweep.osw

Use of an LFO to sweep the center frequency of a bandpass filter. Experiment with different LFO waveforms and frequencies. It's fun!

audio/lofi_crusher.osw

Lower the effective sample rate and bit resolution of a signal. This simple "lo-fi" effect is currently quite popular in electronic music.

audio/looping.osw

Playback and control of a sample loop. Includes time/pitch scaling via time machines.

audio/mixing_two_signals.osw

Using the synchronous addition operator to mix two signals. In general, use of Mixer is preferred.

audio/noisy_resonances.osw

A noise signal is used to excite a bank of resonant filters. The effect sounds vaguely like blowing into a resonant chamber. Replace the noise with an impulse to hear how the same resonant system sounds when struck.

audio/phaser1.osw

Phase shifter with single allpass stage.

audio/phaser6.osw

Phase shifter with six allpass stages. Similar to fx::PhaseShifter transform.

audio/phase_shifter_1_demo.osw

Demo using single-stage phase-shifter patch.

audio/phase_shifter_6_demo.osw

Demo using six-stage phase-shifter patch.

audio/pulse_train.osw

Using the sinc table to produce a pseudo-pulse-train signal.

audio/pwm.osw

A classic "pulse-width modulation" effect using the Square transform.

audio/recording.osw

A simple example of recording audio input to a file in OSW.

audio/ring_modulator.osw

This patch multiplies an incoming signal by a sinewave of variable frequency. The result is a classic "ring modulation" effect. Note that because two synchronous signals are being multiplied, the synchronous multiplication operator '* is used.

audio/signal_compare.osw

Use of a comparison operator with signals.

audio/signal_exp.osw

Applying the exponentiation operator (^) to signals. Note the behavior of even and odd exponents on a sinewave input.

audio/signal_sym_shift.osw

As the source signal is bit-shifted in one direction and then another, information from the original signal is lost. Large bit shifts create a "lo-fi" effect.

audio/signal_xor.osw

Application of the bitwise XOR operator to signals.

audio/simple_fm.osw

Simple FM synthesis in which a sinusoid modulates the frequency of the another sinusoid.

audio/step_modulated_pulses.osw

Use of the step modulator to select frequencies for a sequence of notes synthesized using the decaying pulses algorithm.

audio/step_modulated_sinewave.osw

Application of the step modulator to the frequency of a sinewave.

audio/step_modulator.osw

A modulation algorithm that returns random integers within a specified range at a variable frequency. This is similar to the "random" waveform in the LFO transform.

audio/swiss_cheese.osw

Application of a bit mask to a signal via the bitwise-AND operator.

audio/tanh_distortion.osw

Simple saturation/distortion by applying Tanh to signals.

audio/time_varying_sinusoid.osw

Sinusoid with variable frequency and amplitude.

audio/variable_allpass_demo.osw

Demo that incorporates allpass tutorial patch. Phase-scaling (delay) properties of allpass are demonstrated by changing allpass coefficient input.

audio/waveshaping_synthesis.osw

Using the WaveTable transform for more general waveshaping synthesis.

Control Flow

control/activepassive.osw

This patch demonstrates the different behaviors of active and passive inlets using an arithmetic operator.

control/detecting_change.osw

The patch detects when there is a change in a stream of input events.

Lists

list/duplicate_elements.osw

Use list transforms to remove duplicate elements.

list/empty_lists.osw

Defining empty lists and applying common list transforms to them.

list/list_arithmetic.osw

Apply arithmetic operators to lists. This results in the list containing the rsults of the operator applied to each element. Operations with two list inputs perform element-by-element operations on both lists.

list/list_cons_expr.osw

Using expressions in the Expr transform to construct lists.

list/list_cons_simple.osw

Compare list definition with Expr and List.

list/list_index_expr.osw

Extracting elements from lists via expressions.

list/list_singleton.osw

A list with a single element.

list/series_approx_1.osw

Approximation of the power series (1/2)ⁿ.

list/series_approx_2.osw

Approximation of the series (1/n)². It's actually rather interesting.

list/series_approx_general.osw

Generalized power-series approximation.

list/sum.osw

A handy little patch that accepts lists and outputs the sum of all the elements in the list. The list::Fold transform is used.

Arithmetic and Mathematical

math/approx_e.osw

A Taylor-series approximation of e.

math/bessel_function.osw

This patch calculates Bessel functions of the 1st kind using a summation approximation. It is not particularly efficient, but demonstrates the use of list transforms in approximate calculations.

math/factorial.osw

Use the This transform to create a recursive patch that implements factorial. This technique is intended as a tutorial, for efficient factorial use the "!" operator of Expr.

math/fib.osw

Use the This transform to create a recursive patch that calculates fibonacci numbers. This technique is more pedagogical than practical; to calculate fibonacci numbers efficiently use the well-known formula based on exponentiation of the golden ratio.

math/hyperb_identities.osw

Various identities on hyperbolic functions.

math/mathexpr1.osw

Compare and contrast two subpatches. One using arithemetic and math-function transforms, one using an expression.

math/slow_bessel_demo.osw

This demo uses the bessel_function tutorial patch. Graphs of resulting Bessel functions are displayed in an inline table. Note: when we say slow we mean it.

math/sum.osw

A handy little patch that accepts lists and outputs the sum of all the elements in the list. The list::Fold transform is used.

math/trig_identities.osw

Various trigonometric identities demonstrated as OSW patches.

MIDI

midi/midi_transpose.osw

Incoming note messages are transposed up a perfect fifth.

Musical-note Processing

music/19_tone.osw

Convert MIDI notes into consecutive pitches in a 19-tone scale. This technique can be easily applied to other equal-temperament scales (e.g., 23-tone, 31-tone, etc.).

music/midi_score.osw

Render an OSW score via MIDI.

music/synth_score.osw

Render an OSW score using synthesis primities (e.g., a Sinewave).

OpenSound Control (OSC)

osc/autoserver.osw

Send messages to the built-in OSC server in OSW.

osc/dumpOSC.osw

A simple OSC server that outputs incoming OSC messages to the console.

osc/invisible_patch.osw

Create an "invisible patch" by sending OSC commands that instantiate and connect transforms.

osc/osc_scriptor.osw

Read a file of OSC commands (address + arguments) and send them to internal server.

osc/osc_server.osw

Create a custom OSC server in OSW.

osc/osc_signal.osw

Send signals via OSC.

osc/sendOSC.osw

Generic OSC client; can be used to control other OSC servers.

Virtual Time and Time Machines

time/rate_controls_pitch.osw

Changing the rate of a time machine that controls a sample player will alter the pitch.

time/switcheroo.osw

Turn various signal generators on or off by rerouting virtual time.