DSSI
This is the Disposable Soft Synth Interface specification & example code repository.
You'll find here:
doc/RFC.txt -- proposed DSSI specification -- read this first
dssi/dssi.h -- DSSI header file -- the comments define those parts of the spec dealing with host/plugin interaction (not covered in RFC)
jack-dssi-host/jack-dssi-host.c -- a simple JACK/ALSA-sequencer plugin host
examples/dssi_osc_send.c
examples/dssi_osc_update.c -- simple DSSI OSC test programs
examples/trivial_synth.c -- a quite useless but fairly clear illustrative synth plugin
examples/less_trivial_synth.c -- a synth that actually does some basic synthesis
examples/less_trivial_synth_qt_gui.cpp -- a very simple Qt GUI for the above
examples/trivial_sampler.c -- a simple one-sample polyphonic mono sampler (that doesn't do proper pitch scaling)
examples/trivial_sampler_qt_gui.cpp -- a very simple Qt GUI for the above
Requirements
In order to install the development files (dssi.h and dssi.pc) needed to compile DSSI applications, you only need the following:
pkgconfig with PKG_CONFIG_PATH set appropriately ALSA 0.9/1.0.x (or libdssialsacompat: see
http://home.jps.net/~musound)
LADSPA SDK 1.x
To build the included host and plugins, you will also need:
JACK
liblo-0.12 or above: http://www.plugin.org.uk/liblo/
libsndfile: http://www.mega-nerd.com/libsndfile/
libsamplerate: http://www.mega-nerd.com/SRC/
To build the less_trivial_synth and trivial_sampler Qt GUIs, you will need:
Qt 3
Note that because DSSI itself is just an API, it is possible to use DSSI applications (say, Rosegarden with Xsynth-DSSI) without any of the hosts or plugins contained in this DSSI distribution. Furthermore, to compile DSSI applications, only the DSSI development files (dssi.h and dssi.pc) are needed. OS distribution maintainers are urged to keep these dependencies in mind when packaging DSSI, and not make their `dssi-devel' package dependent on JACK or Qt, for example.
Build
DSSI can be installed using the usual autoconf/automake `./configure && make && make install' procedure. See the included file INSTALL for generic installation instructions.
You will need to ensure PKG_CONFIG_PATH is set correctly to locate the pkgconfig files for ALSA or libdssialsacompat, liblo, JACK, sndfile, and samplerate. You may also need to set the QTDIR and/or QTINCDIR variables to point to your Qt installation. If you do not have any of these, any DSSI programs or plugins dependent on them will not be built.
For example, to build on Debian I use:
$ QTDIR=/usr
$ QTINCDIR=/usr/include/qt3
$ PKG_CONFIG_PATH=/usr/lib/pkgconfig
$ export QTDIR QTINCDIR PKG_CONFIG_PATH
$ ./configure
$ make && make check
After compiling, optionally test the host and example plugins (see below) and then run `make install' from the top-level directory to install the dssi header, dssi.pc pkgconfig file, and the host and examples. The default install prefix is /usr/local.
Test
The quickest test (provided your system has all the required software, you've done `make install', and JACK is running) is just to run `less_trivial_synth' or `trivial_sampler', which should have been installed in your $PREFIX/bin. These should simply start up a standalone sampler/synth with a GUI window. If these both work, pretty much everything else should.
Here's a more descriptive test:
Assuming you've built the host and plugins, installed them to /usr/local, and JACK is running, you may run:
$ export DSSI_PATH=/usr/local/lib/dssi $ /usr/local/bin/jack-dssi-host less_trivial_synth.so
A synth GUI should pop up, with an ALSA sequencer input and JACK output (connected by default to the first alsa_pcm out). If you connect a MIDI keyboard (or vkeybd) to its ALSA MIDI input, you should be able to play it and use MIDI controllers to adjust its parameters: MIDI CC1 (the modulation wheel) controls timbre, and controllers 72, 73, 75 and 79 control release, attack, decay and sustain respectively (some keyboards already have controls set up for these values).
What has actually happened (if it worked) is that the host has been started, has loaded the first synth plugin (labelled LTS) found in the given .so file, has located the GUI executable that the make procedure installed into examples/less_trivial_synth/LTS_qt, instantiated the plugin, started the GUI and is now managing the MIDI input from ALSA, control changes from the GUI and audio out to JACK.
You may also run multiple synth instances simultaneously with this host:
$ export DSSI_PATH=/usr/local/lib/dssi $ export PATH=$PATH:/usr/local/bin # if it's not there already $ jack-dssi-host -2 less_trivial_synth.so -3 trivial_sampler.so
This will create two less_trivial_synth instances and three trivial_sampler instances. Note that the instances are assigned consecutive MIDI channels, and their outputs are spread across all of the available JACK physical outputs.
Licensing
The DSSI API itself (dssi.h) is licensed under the GNU Lesser General Public License. See COPYING for details.
The jack-dssi-host is provided under a BSD-style license. This means you can do anything you want with it so long as you retain the copyright attribution and license information. See the source files for details.
Licensing for the files in the examples directory may vary: please check the individual files for details. Most of them are in the public domain, which means you can use them for anything you want.