videotimecode: We only support 30000/1001 and 60000/1001 as drop-frame framerates

24000/1001 is *not* a drop-frame framerate.

gst-libs/gst/video/gstvideotimecode.c

@@ -94,6 +94,14 @@ gst_video_time_code_is_valid (const GstVideoTimeCode * tc)
     return FALSE;
   }
 
+  /* We only support 30000/1001 and 60000/1001 as drop-frame framerates.
+   * 24000/1001 is *not* a drop-frame framerate! */
+  if (tc->config.flags & GST_VIDEO_TIME_CODE_FLAGS_DROP_FRAME) {
+    if (tc->config.fps_d != 1001 || (tc->config.fps_n != 30000
+            && tc->config.fps_n != 60000))
+      return FALSE;
+  }
+
   /* Drop-frame framerates require skipping over the first two
    * timecodes every minutes except for every tenth minute in case
    * of 30000/1001 and the first four timecodes for 60000/1001 */