Remove INFINITY as suggested by rich.

Originally committed as revision 12289 to svn://svn.ffmpeg.org/ffmpeg/trunk

cmdutils.c

@@ -128,7 +128,7 @@ unknown_opt:
             } else if (po->flags & OPT_INT64) {
                 *po->u.int64_arg = parse_number_or_die(opt+1, arg, OPT_INT64, INT64_MIN, INT64_MAX);
             } else if (po->flags & OPT_FLOAT) {
-                *po->u.float_arg = parse_number_or_die(opt+1, arg, OPT_FLOAT, -INFINITY, INFINITY);
+                *po->u.float_arg = parse_number_or_die(opt+1, arg, OPT_FLOAT, -1.0/0.0, 1.0/0.0);
             } else if (po->flags & OPT_FUNC2) {
                 if(po->u.func2_arg(opt+1, arg)<0)
                     goto unknown_opt;