Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/spotlightkid/nymph

A Nim library for writing audio and MIDI plugins conforming to the LV2 standard
https://github.com/spotlightkid/nymph

faust-dsp lv2 lv2-plugins nim-l

Last synced: 27 days ago
JSON representation

A Nim library for writing audio and MIDI plugins conforming to the LV2 standard

Awesome Lists containing this project

README 

        
# nymph



A [Nim] library for writing audio and MIDI plugins conforming to the [LV2]

standard



## Examples



Build the `amp.lv2` example plugin:



    nimble build_ex amp



Check the `amp.lv2` plugin bundle with `lv2lint`:



    nimble lv2lint amp



Run the `lv2bm` benchmark with the `amp.lv2` plugin:



    nimble lv2bm amp



Install the `amp.lv2` example plugin:



    cp -a examples/amp.lv2 ~/.lv2



Other example plugins can be found in the [examples](./examples) directory and

can be built and tested with similar commands. Just change the example name to

the basename of the plugin's LV2 bundle dir.



Currently, there are just a few other example plugins:



* [`miditranspose`](./examples/miditranspose_plugin.nim): shows how to handle

  receiving and sending MIDI events.

* [`multimodefilter`](./examples/multimodefilter_plugin.nim): shows a

  multimode state-variable filter implementation ported from C++ to Nim.

* [`tiltfilter`](./examples/titltfilter_plugin.nim): shows a multimode tilt

  equalizer filter implementation ported from Rust to Nim.

* [`faustlpf`](./examples/faustlpf_plugin.nim): shows how to integrate DSP C

  code generated from a [FAUST] source file in Nim (in this example the FAUST

  code implements a simple non-resonant low-pass filter from the FAUST

  standard library).



## How To



**Note:** I'll use `mydsp` as the base name for the new plugin in the

examples below. Substitute your own plugin basename wherever you see it used

below.



1. Install this library:



      nimble install https://github.com/SpotlightKid/nymph.git



1. Make a directory named `mydsp.lv2` and copy `examples/amp.lv2/manifest.ttl`

    into it. Also copy `examples/amp.lv2/amp.ttl` to `mydsp.lv2/mydsp.ttl`.



1. Copy `examples/amp_plugin.nim` into your project as `mydsp_plugin.nim`.



1. Edit `mydsp.lv2/manifest.ttl`:

   * Change the plugin URI.

   * Change the plugin's shared library name defined via `lv2:binary` to

     `libmydsp.so`.

   * Change file name referenced via `rdfs:seeAlso` to `mydsp.ttl`.



1. Edit `mydsp.lv2/mydsp.ttl`:

   * Change the plugin URI.

   * Define audio, control and atom ports as needed.



1. Edit `mydsp_plugin.nim`:

   * Change the `PluginUri` constant at the top.

   * Change the `PluginPort` enum and list the ports in the order defined in

     `mydsp.ttl`.

   * Rename and update the definition of the `AmpPlugin` object type and

     define its members with the appropriate data types for the plugin ports

     they will be connected to. Update the type name in the `instantiate`,

     `deactivate`, `connectPorts` and `run` procs.

   * Update and extend the `case` statement in `connectPort` to connect ports

     to your plugin object instance members.

   * Implement your DSP code in the `run` proc.



1. Compile the plugin shared library object with:



        nim c --app:lib --noMain:on --mm:arc \

            --out:mydsp.lv2/libmydsp.so mydsp_plugin.nim



   See the definition of the `build_ex` task in the

   [nymph.nimble](./nymph.nimble#L67) file on how to create a nimble task

   to simplify compilation and additional compiler args you might want to use.



## Dependencies



Required:



* [Nim] >= 2.0



Optional:



* [lv2bm] - For benchmarking and stress-testing plugins

* [lv2lint] - For checking conformity of plugin bundles



## See Also



* [lv2-nim](https://gitlab.com/lpirl/lv2-nim) - Older third-party Nim bindings

  for the LV2 audio plugin specification. Last update in 2021.

* [offbeat](https://github.com/NimAudio/offbeat) - A [CLAP] based plugin

  framework in Nim



[CLAP]: https://cleveraudio.org/

[FAUST]: https://faust.grame.fr/

[LV2]: https://lv2plug.in/

[lv2bm]: https://github.com/moddevices/lv2bm

[lv2lint]: https://git.open-music-kontrollers.ch/~hp/lv2lint

[Nim]: https://nim-lang.org/