// and maxBands is the maximum number of bands a window can
	// span in any alignment.
	minBands := int((int64(window) + c.bandDur - 1) / c.bandDur)
	maxBands := int((int64(window) + 2*(c.bandDur-1)) / c.bandDur)
	if window > 1 && maxBands < 2 {
		panic("maxBands < 2")
	}
	tailDur := int64(window) % c.bandDur
	nUtil := len(c.bands) - maxBands + 1
	if nUtil < 0 {
		nUtil = 0
	}