--- cvsroot/CV/Makefile.PL	2018/09/23 07:04:26	1.54
+++ cvsroot/CV/Makefile.PL	2021/01/04 04:49:04	1.55
@@ -13,6 +13,7 @@
 **
 ** Optional dependencies:
 ** apt-get install libwebp-dev
+** jpeg-xl reference implementation
 **
 
 EOF
@@ -31,6 +32,12 @@
    $lib .= " " . qx<pkg-config --libs   libwebp libwebpdemux>;
 }
 
+if (!system "pkg-config --exists libjxl libjxl_threads") {
+   $inc .= " -DJXL=1";
+   $inc .= " " . qx<pkg-config --cflags libjxl libjxl_threads>;
+   $lib .= " " . qx<pkg-config --libs   libjxl libjxl_threads>;
+}
+
 $pkg->add_deps ("Gtk2", "Glib");
 $pkg->set_libs ($lib);
 $pkg->set_inc  ($inc);