static L<IntRange> markerIntRangesForWAV(File f, BWImage freqImage) {
  Clip clip = spectro_clipFromFile(srcWAV);
  L<Int> intMarkers = sorted(allToInt(markers));
  
  // odd number of markers => clip to end
  if (oddLength(intMarkers)) intMarkers.add(freqImage.getWidth());
  
  ret intsToIntRanges(intMarkers);
}