I’ve been wanting to build this for a while, and it’s finally here!
audio_flux is a package that leverages flutter_soloud for visualizing audio output and flutter_recorder for audio input.
It includes two built-in visualizers, one using CustomPainter and another powered by shaders. The example project features several shaders, made possible with shader_buffer. Adding custom shaders is simple, you can create your own or adapt existing ones from ShaderToy, as they can be (almost) easily copy-pasted and used by audio_flux.
If anyone wants to try it out, provide feedback, or contribute new shaders, here are the links:
web demo
GitHub
Pub.dev