Introduction

dlsynth is a software synthesizer library that parses DLS files (as used by DirectMusic) and outputs audio data.

Examples

dlsynth exposes a pure C interface for ease of use from other languages:

#include <stdio.h>
#include <dlsynth.h>

int main() {
  struct dlsynth_sound* snd;
  int err;
  if((err = dlsynth_load_sound_file("myfile.dls", 44100, &snd))) {
    fprintf(stderr, "Could not load file\n");
    return 1;
  }

  struct dlsynth_instr* instr;
  if((err = dlsynth_get_instr_num(0, snd, &instr))) {
    fprintf(stderr, "Could not load instrument\n");
    return 1;
  }

  struct dlsynth* synth;
  if((err = dlsynth_init(
      44100, /* Output sample rate */
      32,    /* Number of voices   */
      &synth))) {
    fprintf(stderr, "Could not init synth\n");
    return 1;
  }

  dlsynth_note_on(synth,
    instr, /* Instrument to use   */
    0,     /* Channel of the note */
    100,   /* Note priority       */
    43     /* MIDI note           */
  );

  int16_t* outputBuffer = /* ... */;

  // Mono rendering
  if((err = dlsynth_render_int16(
        synth, numFrames,
        outputBuffer, NULL,
        1, 1.0f))) {
    fprintf(stderr, "Could not render buffer\n");
    return 1;
  }

  // Interleaved stereo rendering
  if((err = dlsynth_render_int16(
        synth, numFrames,
        outputBuffer, outputBuffer + 1,
        2, 1.0f))) {
    fprintf(stderr, "Could not render buffer\n");
    return 1;
  }

  // Sequential stereo rendering
  if((err = dlsynth_render_int16(
        synth, numFrames,
        outputBuffer, outputBuffer + numFrames,
        1, 1.0f))) {
    fprintf(stderr, "Could not render buffer\n");
    return 1;
  }

  dlsynth_free(synth);
  dlsynth_free_sound(snd);
}

Including dlsynth in an application

A fork of the vcpkg package manager is available here that includes a portfile for dlsynth. You can install it by requesting the HEAD version:

vcpkg install dlsynth --head

On Debian-based distros (like Ubuntu) you can add the libdmusic PPA:

sudo add-apt-repository ppa:libdmusic/unstable

then run

sudo apt update
sudo apt install libdlsynth-dev

You can then use dlsynth as any other CMake-available library:

find_package(dlsynth CONFIG REQUIRED)
target_link_libraries(my_app PRIVATE libdmusic::dlsynth)

Building

Using vcpkg

After having cloned and build vcpkg, install riffcpp:

vcpkg install riffcpp

You will then be able to build dlsynth:

mkdir build
cd build
cmake -DCMAKE_TOOLCHAIN_FILE=path/to/vcpkg/scripts/buildsystems/vcpkg.cmake ..
cmake --build .

dlsynth can be built to use either static or dynamic linking for its dependencies, and itself is able to be built a dynamic or static library

Without vcpkg

You will need to obtain a binary copy of riffcpp and its headers and install it somewhere CMake can find it.

Under Debian-based distros (like Ubuntu) you can add the following line to /etc/apt/sources.list.d/libdmusic.list:

deb [trusted=yes] https://repo.libdmusic.org/apt/ /

then run

sudo apt update
sudo apt install libriffcpp-dev

After cloning the repo, run the following commands:

mkdir build
cd build
cmake .. # -DCMAKE_PREFIX_PATH=/path/to/riffcpp if riffcpp was not installed in the $PATH
cmake --build .

If you also want to install it:

cmake --build . --target install

You can change the path where the library is installed by changing the CMAKE_INSTALL_PREFIX value during configuration.