use CLOCK_FREQ in date_Decrement

src/misc/mtime.c

@@ -212,7 +212,7 @@ mtime_t date_Increment( date_t *p_date, uint32_t i_nb_samples )
  */
 mtime_t date_Decrement( date_t *p_date, uint32_t i_nb_samples )
 {
-    mtime_t i_dividend = (mtime_t)i_nb_samples * 1000000 * p_date->i_divider_den;
+    mtime_t i_dividend = (mtime_t)i_nb_samples * CLOCK_FREQ * p_date->i_divider_den;
     p_date->date -= i_dividend / p_date->i_divider_num;
     unsigned i_rem_adjust = i_dividend % p_date->i_divider_num;