diff --git a/src/util.py b/src/util.py
--- a/src/util.py
+++ b/src/util.py
@@ -1,5 +1,8 @@
+import math
 import os
 import sys
+import collections
+from datetime import datetime
 
 
 def spawnDaemon(fun):
@@ -45,22 +48,61 @@ class Progress:
 		self._i0=i0
 		self._i=i0
 		self._last=""
+		self._past=collections.deque()
 
 	def p(self,i):
 		i0=self._i0
 		n=self._n
+		now=datetime.now()
 
 		assert i0<=i<n or n<i<=i0, (i0,i,n)
 		percentage=Progress._p(i,n,i0)
 		res="{0}%".format(percentage)
-		if res!=self._last:
-			print(res,end="\r")
+		if len(self._past)==0 or (now-self._past[-1][0]).total_seconds()>1:
+			self._past.append((now,i))
+		if res!=self._last or (now-self._past[0][0]).total_seconds()>5:
+			eta=formatSeconds(self.eta(i))
+			self._print("{0} (ETA {1})".format(res,eta))
 			self._last=res
+			while (now-self._past[0][0]).total_seconds()>5:
+				self._past.popleft()
 
 	def done(self):
-		print("100%")
+		self._print("100%",end="\n")
+
+	def eta(self,i2):
+		t2=datetime.now()
+		(t1,i1)=self._past[0]
+		if i2==i1: return float("nan")
+		return (self._n-i2)/(i2-i1)*(t2-t1).total_seconds()
 
 	@staticmethod
 	def _p(i,n,i0):
 		_1=1 if n>=i0 else -1
 		return 100*(i+_1-i0)//(n-i0)
+
+	def _print(self,s,end=""):
+		print("\r"+" "*80,end="")
+		print("\r"+s,end=end)
+
+
+def formatSeconds(secs):
+	if math.isnan(secs): return "?"
+	secs=round(secs)
+	if secs<60: return "{0}s".format(secs)
+	mins=secs//60
+	secs%=60
+	if mins<60: return "{0:02}:{1:02}".format(mins, secs)
+	hours=mins//60
+	mins%=60
+	return "{0:02}:{1:02}:{2:02}".format(hours, mins, secs)
+
+
+if __name__=="__main__":
+	import random
+	import time
+	progress=Progress(100)
+	for i in range(1,100):
+		progress.p(i)
+		time.sleep(random.random()*2)
+	progress.done()