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Usage Documentation

Directory Structure:

The top level distribution contains the following directories:

This release of STK comes with four separate "project" directories:

  1. The demo project is used to demonstrate nearly all of the STK instruments. The stk-demo program has been written to allow a variety of control input and sound data output options. Simple graphical user interfaces (GUIs) are also provided.

  2. The effects project demonstrates realtime duplex mode (simultaneous audio input and output) operation, when available, as well as various delay-line based effects algorithms.

  3. The ragamatic project is just cool. Fire it up and be enlightened.

  4. The eguitar project demonstrates how to make an electric guitar with feedback and distortion.

  5. The examples project contains several simple programs that demonstrate audio input/output, including the audio internet streaming classes, as well as most of the tutorial programs.


For those who wish to create their own system-specific Makefiles:


When developing applications with STK, it is recommended that you define the preprocessor definition _STK_DEBUG_ when compiling (or specify the –enable-debug option to the configure script). This will enable all levels of function argument and error checking within the STK classes. Without this definition, argument checking does not occur in functions that are expected to be called frequently in an iterative manner.

Control Data:

All STK programs in this distribution take input control data in the form of SKINI or MIDI messages only. The Messager class unifies the various means of acquiring control data under a single, easy to use set of functions. The way that SKINI messages can be sent to the programs is dependent upon the operating system in use, as well as whether the program is running in realtime or not. In general, it is possible to:

  1. Redirect or pipe SKINI scorefiles to an executable.
  2. Pipe realtime SKINI input messages to an executable (not possible under Windows95/98).
  3. Acquire realtime MIDI messages from a MIDI port on your computer.

Tcl/Tk graphical user interfaces (GUI) are provided with this distribution that can generate realtime SKINI messages. Note that the Messager class allows multiple simultaneous socket client connections, together with MIDI and/or piped input. The Md2Skini program (in the demo directory) is mostly obsolete but can be used to create SKINI scorefiles from realtime MIDI input.

Demo: STK Instruments

The demo project demonstrates the behavior of all the distributed STK instruments. The instruments available with this release include:

Demo: Non-Realtime Use

See the information above with respect to compiling STK for non-realtime use.

In non-realtime mode, it is assumed that input control messages are provided from a SKINI scorefile and that audio output is written to a soundfile (.snd, .wav, .aif, .mat, .raw). A number of SKINI scorefiles are provided in the scores directory of the demo project. Assuming a successful compilation of the stk-demo program, typing:

stk-demo BeeThree -ow myfile.wav -if scores/bookert.ski

from the demo directory will play the scorefile bookert.ski using the STK BeeThree instrument and write the resulting audio data to a WAV formatted soundfile called "myfile.wav" (note that you may need to append ./ to the program name if your default shell setup is not set to look in the current directory). Typing stk-demo without any arguments will provide a full program usage description.

Demo: Realtime Use

STK realtime audio and MIDI input/output and realtime SKINI control input via socketing support is provided for Linux, Mac OS-X, and Windows95 and later operating systems. STK realtime SKINI control input via piping is possible under Linux, Mac OS X, and Windows2000 and later only.

Control input and audio output options are typically specified as command-line arguments to STK programs. For example, the stk-demo program is invoked as:

stk-demo instrument flags

where instruments include those described above and flags can be any or all of:

The -ip flag must be used when piping realtime SKINI control data to an STK program. The -im flag must be used to read MIDI control input from your MIDI port. Note that you can use both input types simultaneously.

Assuming a successful compilation of the stk-demo program, typing:

stk-demo BeeThree -or -if scores/bookert.ski

from the demo directory will play the scorefile bookert.ski using the STK BeeThree instrument and stream the resulting audio data in realtime to the audio output channel of your computer. Typing stk-demo without any arguments will provide a full program usage description.

Realtime Control Input using Tcl/Tk Graphical User Interfaces:

There are a number of Tcl/Tk GUIs supplied with the STK projects. These scripts require Tcl/Tk version 8.0 or later, which can be downloaded for free over the WWW. On Unix and Windows2000 and later platforms, you can run the various executable scripts (e.g. StkDemo.bat) provided with each project to start everything up (you may need to symbolically link the wishXX executable to the name wish). The Physical.bat script just implements the following command-line sequence:

wish < tcl/Physical.tcl | stk-demo Clarinet -or -ip

Realtime MIDI Control Input:

On all supported realtime platforms, you can direct realtime MIDI input to the STK Clarinet by typing:

stk-demo Clarinet -or -im

This will attempt to use the default MIDI port for input. An optional MIDI port number can be specified after the -im flag. Valid MIDI ports are numbered from 0 (default) and higher. On Linux and Macintosh OS-X systems, it is possible to open a virtual MIDI input port (that other software applications can connect to) by specifying a port identifier of -1.


The stk-demo program supports an arbitrary number of voices via the -n NUMBER command-line flag and argument. For example, you can play eight BeeThree instruments with realtime output and control them from a MIDI device by typing:

stk-demo BeeThree -n 8 -or -im

The Synthesis ToolKit in C++ (STK)
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