Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/fhunleth/midi_synth
Play music in Elixir
https://github.com/fhunleth/midi_synth
elixir fluidsynth hacktoberfest midi
Last synced: 3 months ago
JSON representation
Play music in Elixir
- Host: GitHub
- URL: https://github.com/fhunleth/midi_synth
- Owner: fhunleth
- License: apache-2.0
- Created: 2018-05-27T20:48:59.000Z (over 6 years ago)
- Default Branch: main
- Last Pushed: 2022-11-18T01:51:51.000Z (about 2 years ago)
- Last Synced: 2024-03-15T04:47:12.038Z (10 months ago)
- Topics: elixir, fluidsynth, hacktoberfest, midi
- Language: Elixir
- Homepage: https://hex.pm/packages/midi_synth
- Size: 65.4 KB
- Stars: 28
- Watchers: 6
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# MIDISynth
[](https://circleci.com/gh/fhunleth/midi_synth)
[](https://hex.pm/packages/midi_synth)
[](https://hex.pm/packages/midi_synth)
[](https://hex.pm/packages/midi_synth)
[](https://github.com/fhunleth/midi_synth)
Play music in Elixir.
## Trying it out
First, install [FluidSynth](http://www.fluidsynth.org/).
On Linux:
```sh
sudo apt install libfluidsynth-dev
```
On MacOS:
```sh
brew install fluidsynth pkg-config
```
Next, either clone this library or pull it in as a dependency to your Elixir
project. The following is an example of the dependency for your `mix.exs`:
```elixir
{:midi_synth, "~> 0.4.0"}
```
Fetch dependencies and build as you normally would. The first build will
download the `FluidR3_GM.sf2` soundfont file. This is a Creative
Commons-licensed data file that contains all of the
[General MIDI](https://en.wikipedia.org/wiki/General_MIDI) instruments. It is a
good place to start, but can be changed later on.
IMPORTANT: If `midi_synth` has a compiler error on MacOS, it is likely that it
is due to an error in a pkg-config file referred to by `fluidsynth.pc`. To fix,
edit `/opt/homebrew/lib/pkgconfig/fluidsynth.pc` and remove the word "readline".
## Try it out using IEx
Start IEx by running `iex -S mix` from a shell prompt.
`MIDISynth` is a `GenServer` and must be started first. The library comes with
with helpers to make playing simple things easy. For more complicated uses,
you'll want to build on this library.
OK, let's play a note. Notes are numbered sequentially. Middle C is note 60.
Here's how to play middle C for 100 ms.
```elixir
iex> {:ok, synth} = MIDISynth.start_link([])
{:ok, #PID<0.226.0>}
iex> MIDISynth.Keyboard.play(synth, 60, 100)
```
You can play the same note with a different velocity. The velocities range from
1 to 127. Here's how to play middle C for 100 ms with velocity mezzo-forte: 80.
```elixir
iex> MIDISynth.Keyboard.play(synth, 60, 100, 80)
```
If you don't like the piano, try switching the instrument to something else.
For example, trumpets [(General MIDI instrument
57)](https://www.midi.org/specifications-old/item/gm-level-1-sound-set) are
nice:
```elixir
iex> MIDISynth.Keyboard.change_program(synth, 57)
iex> MIDISynth.Keyboard.play(synth, 60, 500)
```
Percussion instruments can be played only through MIDI channel 9.
For example, this is how to play a cowbell sound:
```elixir
iex> MIDISynth.Keyboard.play(synth, 56, 0, 127, 9)
```
The real value of this library is the ability to send raw MIDI messages to the
FluidSynth library. The Elixir code barely scratches the surface of what's
possible. If you're comfortable with raw [MIDI
commands](https://www.midi.org/specifications/item/table-1-summary-of-midi-message),
try this out:
```elixir
iex> MIDISynth.midi(synth, <<0x90, 60, 127>>)
iex> MIDISynth.midi(synth, <<0x80, 60, 127>>)
```
See `MIDISynth.Command` for help with encoding messages, and please feel free to
add more.
## License
The Elixir and C code are covered by the Apache 2 License.