Rust Audio

Announcement: rsynth version 0.1.0

:tada: I’m super proud to have released version 0.1.0 of rsynth to rsynth is mostly an abstraction layer for different audio “backends” (jack, vst, …), but it also has some utilities for “streaming” audio processing.

The previous version, version 0.0.1 was published nealry two years ago by @doomy and a lot has happended then since.
Most obviously, @doomy has transferred rsynth to my account. Thanks a lot for the trust you place in me, @doomy !

Also on a technical level, a lot – nearly everything – has changed.

  • Added support for jack as a backend
  • An abstraction for audio buffers (it’s not obvious when you read the source code and using it is rather smooth, but oh my, this caused me a lot of headscratches to get the borrow checker happy)
  • Support for offline rendering
  • A backend independent mechanism for specifying meta-data. It also has a “user friendly” way for specifying the eta-data, but maybe it’s a little to “automagic”? I don’t know, future will tell.
  • Lots of edits to the documentation
  • Two crates were developed specifically for rsynth: vecstorage and midi-consts (+ two extra crates that I would not recommend and that are no dependencies of rsynth anymore)
  • Lots and lots of refactoring big and small

There are also some things that didn’t make it to this release

  • The concept of middleware and pipleines, similar to what you have in web development. This didn’t make it for a good reason: it just adds a lot of complexity and compile times for no real gain.
  • Support for reading midi files with rimd. I removed it because I was using the master branch from GitHub and only supports specifying dependencies from See this issue for more info. It’s a pitty, but nothing that can’t be solved in the future.

What’s in there for the future?

Telling the future is not one of my capabilities, but if we look back at two years of history now, we see that rsynth development has been rather stable for a long time. The git logs do not always show that because I tend to squash my own commits now (who looks at previous versions anyway?) and because I have also been trying out rsynth in some private projects.
So overall, rsynth has been an ongoing effort for nearly two years now and we can expect it to continue in the future.

Nevertheless, let’s be honest: rsynth is a one-person project right now, so there are some constraints. We’ve all seen some of the best people in the Rust community get burn-outs and, while there are currently no signs of that happening to me, it’s something to watch out for.
The most important aspect, I think, is scope management: keeping the scope small enough so that it’s still doable for one person. In practice, this means limiting the scope to only features that I personally use. This has the additional benefit that it’s all tested: it’s not just an API that can be used in theory, you can also use it in practice.

So, what’s in features will I likely need in the future? It’s hard to tell, but it’s probably better envelopes (the ones that are in there right now are rather embryotic) and support for lv2.

Does this mean there are no other features possible? Definitely not. If there is something you would like to see, you can open a pull request. Also, rsynth is designed to be modular, so not everything needs to be in the rsynth crate or repository.

Edit: writing and editing this post and discussing it with a friend made me understand that the scope of rsynth is in fact too vague and too broad. So the future of rsynth is probably focusing on API abstractions and moving everything else (polyphony, envelopes, …) to separate crates.

Whether you will use rsynth or not … happy coding!


Thank you so much for this project. I built the examples, run jack_synth, connected jack-keyboard and the outputs, and the thing actually made a sound! It was uncanny to be able to make a (more or less :slight_smile: ) working Jack application so easily.

I’m going to try to port to it some code I wrote. I’m also quite interested in lv2 plugins too. Great work!

Hi @teknico, thanks for your enthousiasm!

If you’re using only the jack back-end, there is not much benefit in using rsynth (I don’t know when the lv2 support will be ready).