diff --git a/ffmpeg-myth.scm b/ffmpeg-myth.scm
index ebed68d..73cc25b 100755
--- a/ffmpeg-myth.scm
+++ b/ffmpeg-myth.scm
@@ -298,10 +298,9 @@
 
 
 (define (recording-new-file-name file-name ending)
-  (let* ((old-ending (substring file-name (- (string-length file-name) 3)))
-	 (n (- (string-length file-name) (if (string=? old-ending ".ts") 3 4))))
-    (simple-format #f "~a.~a" (substring file-name 0 n) ending)))
-
+  (let* ((base+exts (string-split file-name #\.))
+	 (base (car base+exts)))
+    (simple-format #f "~a.~a" base ending)))
 (define* (create-record-data-for-transcode rec)
   (let* ((rtn-list '())
 	 (tr-rec rec)