urmusic is a free and open-source software that allows you to easily create your own music visualizer and create a music video for it!
It makes use of hardware acceleration to render frames as fast as possible.
Donations:
Support me on ko-fi: https://ko-fi.com/nasso
JAviSynth is a wrapper library that allows AviSynth to be used in the Java programming language. Through JNI, it provides access to the input and video processing capabilities of AviSynth. Videos and scripts can be opened, manipulated and viewed.