diff --git a/libavcodec/faandct.c b/libavcodec/faandct.c
index c7388fb4de..e503f2f681 100644
--- a/libavcodec/faandct.c
+++ b/libavcodec/faandct.c
@@ -16,6 +16,7 @@
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
+ * this implementation is based upon the IJG integer AAN DCT (see jfdctfst.c)
  */
 
 /**