Noisemaker is a digital audio synthesizer library. Using this library, the user can design a sound and that sound can be written to a wav file. Its development was largely informed by Computer Music: Synthesis, Composition, and Performance by Charles Dodge, so Noisemaker may also serve as a supplement to that book, particularly Chapter 3.

Installation

Disclaimer: Installation instructions are given for Windows and MacOS but serious bugs exist on the Windows build and the Mac build is untested.

For starters, you'll need a C++ compiler and the C++ standard library. Instructions for installing a compiler can be found here The project must be compiled with C++11 or higher.

For Windows Users: Note that if you use MinGW (as is recommended) on Windows, you'll have to make sure you install the mingw32-gcc-g++-bin and mingw32-make-bin packages and add them to your path. Otherwise you'll have to use a different generator for CMake and you're on your own.

Other requisite software

You need to install cmake.

On Linux, you can simply run

apt install cmake

Or on MacOS, run

brew install cmake

For Windows systems, you can find the latest version of CMake here. Make sure you add cmake to your path.

Libraries required for building the documentation

You need to have Python 3 installed no matter what operating system you're using. On Windows, make sure that you add python and pip3 to your path.

Linux:

apt install doxygen
pip3 install sphinx sphinx_rtd_theme breathe

MacOS:

brew install doxygen
pip3 install sphinx sphinx_rtd_theme breathe

Windows:

Doxygen can be downloaded here. Then you can run:

pip3 install sphinx sphinx_rtd_theme breathe

Install instructions

To start, make a build directory in the project:

mkdir build
cd build

Then run, on MacOS or Linux, run

cmake ..

Or, to build the documentation too, run

cmake -DBUILD_DOCS=ON ..

On Windows, you should run

cmake .. -G "MinGW Makefiles"

Again, to build the documentation, you'll need to run

cmake -DBUILD_DOCS=ON -G "MinGW Makefiles" ..

If it works, it should look something like this:

jack@the-machine:/mnt/c/Users/99jac/Documents/noisemaker/build$ cmake ..
-- The C compiler identification is GNU 7.4.0
-- The CXX compiler identification is GNU 7.4.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /mnt/c/Users/99jac/Documents/noisemaker/build

The next step is to do:

cmake --build .

Now you can do several things:

• Read the docs : If you build the documentation and all goes as planned, among other things you should now find a file called build/docs/sphinx/index.html and if you point a browser at it, you can read the documentation.

• Run one of the already written main programs that makes some sound.

  cd tests
  ./NoisemakerTests
  

  That creates an output file called test.wav which you can play in Audacity, or your favorite media player.

  The the other one is:

  ./Megalovania
  

  The source for each of these is in: $ROOT/tests/*.cpp

Building on Linux without sudo privilages

To build this on Linux without sudo privilages, you will need to do:

pip3 install --user sphinx
export PATH=${HOME}/.local/bin:${PATH}
mkdir build
cd build
cmake ..
cmake --build .

Usage

The basic workflow in Noisemaker is as follows:

1. Create a custom instrument using Noisemaker classes
2. Read the samples of that instrument into an array
3. Write those samples into a wav file

Below is an exaple of how to create a 440hz sine wave:

#include "noisemaker.h"
#include "oscillator.h"
#include "premadeSignals.h"
#include "filefuncs.h"

writableSample samples[100000];
Oscillator o = formSineWave(440);

for (int i = 0; i < numSamples; i++) {
 samples[i] = (writableSample) o.step();
}

writeWavFile(fopen("test.wav", "w"), samples, numSamples, noisemaker::sampleRate);

writableSample is the type that noisemaker uses to store samples. Right now it should be int_16_t.

Oscillator is a subclass of the Signal class. All Signals have a step() function that returns the next sample that the Signal has generated. Here we use the premade Oscillator returned by the sineWave function. It returns samples that make a sine wave at the specified frequency.

In the following for loop, we write Oscillator's step() values to an array. We cast them from sample to writableSample, because that is the data type that writeWavFile expects.

Finally we pass that array to the writeWavFile function. Its parameters are self-explanatory.