diff -up mjpegtools-1.9.0/lavtools/png2yuv.c~ mjpegtools-1.9.0/lavtools/png2yuv.c
--- mjpegtools-1.9.0/lavtools/png2yuv.c~	2007-11-08 18:31:50.000000000 +0100
+++ mjpegtools-1.9.0/lavtools/png2yuv.c	2010-09-03 13:32:43.015596001 +0200
@@ -407,6 +407,7 @@ int decode_png(const char *pngname, int 
     return 2;
     }
 
+  png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
   fclose(pngfile);
 
   return 1;