GetSpectrumData over entire file

Yes it's possible. you can do it to any degree of complexity, like take 6400 arrays of 64 samples from a 6400 sample long audio file, each one has 1 sample later....

Then you would be writing a waterfall display, i.e. a line of fft values at the top drawing a large 3d array. easily stored in image files.

for a reasonable start, take a 2 second audio file, analyse 1000 segments from it of 256 frequencies, and write the results to a 3d array. then go with further detail if you want. please post the time it takes to analyse it, am curious.