diff -urN mplayer-1.0_rc4_p20100506-orig/cfg-mencoder.h mplayer-1.0_rc4_p20100506/cfg-mencoder.h
--- mplayer-1.0_rc4_p20100506-orig/cfg-mencoder.h	2010-05-04 08:34:38 +0900
+++ mplayer-1.0_rc4_p20100506/cfg-mencoder.h	2010-05-07 13:13:53 +0900
@@ -189,6 +189,7 @@
     {"skiplimit", &skip_limit, CONF_TYPE_INT, 0, 0, 0, NULL},
     {"noskiplimit", &skip_limit, CONF_TYPE_FLAG, 0, 0, -1, NULL},
     {"noskip", &skip_limit, CONF_TYPE_FLAG, 0, 0, 0, NULL},
+    {"nodup", &dup_limit, CONF_TYPE_FLAG, 0, 0, 0, NULL},
 
     {"audio-density", &audio_density, CONF_TYPE_INT, CONF_RANGE|CONF_GLOBAL, 1, 50, NULL},
     {"audio-preload", &audio_preload, CONF_TYPE_FLOAT, CONF_RANGE|CONF_GLOBAL, 0, 2, NULL},
diff -urN mplayer-1.0_rc4_p20100506-orig/mencoder.c mplayer-1.0_rc4_p20100506/mencoder.c
--- mplayer-1.0_rc4_p20100506-orig/mencoder.c	2010-03-25 05:43:41 +0900
+++ mplayer-1.0_rc4_p20100506/mencoder.c	2010-05-07 13:13:04 +0900
@@ -164,6 +164,7 @@
 double force_fps=0;
 static double force_ofps=0; // set to 24 for inverse telecine
 static int skip_limit=-1;
+static int dup_limit=-1;
 float playback_speed=1.0;
 
 static int force_srate=0;
@@ -1570,7 +1571,7 @@
 videosamples++;
 videorate+=(GetTimerMS() - ptimer_start);
 
-if(skip_flag<0){
+if(dup_limit!=0 && skip_flag<0){
     // duplicate frame
 	if(!quiet) mp_msg(MSGT_MENCODER, MSGL_WARN, MSGTR_DuplicateFrames,-skip_flag);
     while(skip_flag<0){