jackclient | Jack audio client library for go

Pay attention to the fact that the last parameter to jack_set_process_callback() is a void *, and it gets passed through to the callback function.

This is a common design pattern with C libraries to make them usable with C++.

What you are going to do is pass this of the object whose method you wish to invoke, as a callback, as the void * with the callback pointer to an extern "C" linkage wrapper function that takes the void *, then reinterpret_casts it back to a class instance pointer, and then invokes its method, something like:

AudioSystem.getAudioInputStream expects a stream which conforms to a supported AudioFileFormat, which means it must conform to a known type. From the documentation:

The stream must point to valid audio file data.

And also from that documentation:

The implementation of this method may require multiple parsers to examine the stream to determine whether they support it. These parsers must be able to mark the stream, read enough data to determine whether they support the stream, and reset the stream's read pointer to its original position. If the input stream does not support these operation, this method may fail with an IOException.

You can create your own AudioInputStream using the three-argument constructor. If the length is not known, it can specified as AudioSystem.NOT_SPECIFIED. Frustratingly, neither the constructor documentation nor the class documentation mentions this, but the other constructor’s documentation does.