diff --git a/compressor/to_filename_out.m b/compressor/to_filename_out.m
new file mode 100644
index 0000000..4082224
--- /dev/null
+++ b/compressor/to_filename_out.m
@@ -0,0 +1,9 @@
+function filename_out = to_filename_out(filename, suffix)
+[dir, name, ext] = fileparts (filename);
+if length(dir)
+	filename_out = sprintf("%s/%s.%s%s", dir, name, suffix, ext);
+else
+	filename_out = sprintf("%s.%s%s", name, suffix, ext);
+end	
+endfunction
+