ratiofpr := targetfps / sourcefps;
for(sec :=0; sec < length; sec++) {
	
	write_frame_0(frame(0));

	source_t := ratio;
	low_fft := fft(source_t, x, y, rgb);
	for (f = 1; f < fps; f++) {
		next_f = ceil(source_t + ratio);
		ratio_ffts := f - source_t;

		next_fft := fft(next_f, x, y, rgb);
		interp := interpolate_ffts(low_fft, next_fft, ratio_ffts);

		pixels := fft(-1, interp);
		write_to_pixel(x, y, pixels[64], rgb);
		source_t += ratio;
		low_fft = next_fft;
	}
}

Frame_complexes : adt {
	frame : big;
	x, y, channel : int;
	complexes : ref Complexes;
	
};


FFT_cache : adt {
	ffts : array of ref frame_complexes;
	fft_ptr : int; # ring buffer pointer
	
	add : fn(f : self ref FFT_cache, fc : ref Frame_complex) : int;
	ffts : fn(f : self ref FFT_cache, frame : big);
};

new_fft_cache(frame : big, x, y, channel, size : int) : ref fft_cache
{
	f := ref FFT_cache(array[size] of ref frame_complexes, 0);
	for(i := 0; i < size; i++)
		f.ffts[i] = ref Frame_complexes(frame, x, y, channel, nil);
	return f;
}


FFT_cache.ffts(f : self ref FFT_cache, frame : big, x, y, channel : int) : ref Complexes;
{
	last := f.ffts[f.fft_ptr]
	if(frame > last.frame || y > last.y || x > last.x || channel > last.channel) {
		f.fft_ptr++;
		f.fft_ptr %= len f.ffts;
		f.ffts[f.fft_ptr] = ref Frame_complexes(frame, x, y, channel, nil);
	}

	ptr := f.fft_ptr;
	for(i := 0; i < len f.ffts; i++) {
		if(f.ffts[i].frame == frame) {
			if(f.ffts[i].complexes == nil) {
				f.ffts[i].complexes = fft->C_from_reals(s.sample_set(frame - 127, frame + 127, x, y, channel));
			return 
	}
}