Vrec.py: don't print Ids if no frames are captured.
Vrecb.py: use the new interfaces to imageop (fix -M, -m, -g options).
diff --git a/Demo/sgi/video/Vrec.py b/Demo/sgi/video/Vrec.py
index d952566..e90a4bd 100755
--- a/Demo/sgi/video/Vrec.py
+++ b/Demo/sgi/video/Vrec.py
@@ -326,13 +326,14 @@
 		print count*200.0/lastid, '%,',
 		print count*rate*200.0/lastid, '% of wanted rate',
 	print
-	print 'Ids:',
-	t0 = ids[0]
-	del ids[0]
-	for t1 in ids:
-		print t1-t0,
-		t0 = t1
-	print
+	if ids:
+		print 'Ids:',
+		t0 = ids[0]
+		del ids[0]
+		for t1 in ids:
+			print t1-t0,
+			t0 = t1
+		print
 	if filename and audiofilename:
 		audiostop.append(None)
 		audiodone.acquire_lock()