This PR is broken into my progress but I better understood the overall design as I worked through all of this, so will try to highlight the main things
renamed fileBuffer for all the internal processing files to be audioBuffer and mFileBuffer to mInputBuffer
The editor now calls mSynth.setInputBuffer to have load the file in and remap it.... THEN once ready we call mSynth.processInput where it actually does the processing
the FFT was being ran twice, set it to be shared across things like the PitchDetector
sjfricke
commented
2 years ago 
This PR is broken into my progress but I better understood the overall design as I worked through all of this, so will try to highlight the main things
fileBufferfor all the internal processing files to beaudioBufferandmFileBuffertomInputBuffermSynth.setInputBufferto have load the file in and remap it.... THEN once ready we callmSynth.processInputwhere it actually does the processingFFTwas being ran twice, set it to be shared across things like the PitchDetector