Allow for parallel pngcrush.sh.

diff --git a/pngcrush.sh b/pngcrush.sh
index d74845aba96aba1e330e0c8c7deab7194689a82d..0598451e6231288f88fb4492a7b86d0c102ec7ba 100755 (executable)
--- a/pngcrush.sh
+++ b/pngcrush.sh
@@ -5,8 +5,8 @@ out=$2
 
 steps=()
 
-src=_.png
-dst=__.png
+src=${out}.src.png
+dst=${out}.dst.png
 
 copy=("${src}" "${dst}")