diff -urN midi_prog-/pitch.c midi_prog/pitch.c
--- midi_prog-/pitch.c	Thu Aug 27 00:00:00 2015
+++ midi_prog/pitch.c	Thu Sep 10 00:00:00 2015
@@ -67,3 +67,70 @@
 		abuf_add(&p->ab, cabs( sbuf_sum_mean_all(&p->sb) ) );
 	}
 }
+
+void
+onoff_stat_init(struct onoff_stat *ost, struct abuf *ab, int ac, char **av)
+{
+	double lmt_sec = opt_double("-lmt_sec", ac, av, 2.0/32);
+	chatt_init(&ost->ct, lmt_sec);
+	chatt_init(&ost->ct2, lmt_sec);
+
+	ost->ab = ab;
+	ost->v = 0;
+	ost->on_sec = -1;
+	ost->off_sec = 0;
+
+	ost->thres = opt_double("-thres", ac, av, 0.03);
+	ost->mean_thres = opt_double("-mean_thres", ac, av, 0.1);
+	ost->mean = -1;
+}
+
+int
+onoff_stat_add(struct onoff_stat *ost, double v, double max_v)
+{
+	struct tbuf *tb = &ost->ab->tb;
+	double sec;
+
+	abuf_add(ost->ab, v);
+	sec = tbuf_newest_sec(tb);
+	return onoff_stat_add_sec(ost, sec, max_v);
+}
+
+int
+onoff_stat_add_sec(struct onoff_stat *ost, double sec, double max_v)
+{
+	struct tbuf *tb = &ost->ab->tb;
+	double v = tbuf_get_dbl(tb, sec);
+	int onoff = v >= max_v * ost->thres;
+	int chg = chatt_add(&ost->ct, sec, onoff), chg2, chg_v = -1;
+
+	if(ost->mean >= 0){
+		ost->mean = abuf_mean(ost->ab, ost->on_sec, sec);
+		chg2 = chatt_add(&ost->ct2, sec, v >= ost->mean * ost->mean_thres);
+	}
+
+	if(!ost->v){
+		if(ost->mean >= 0 && chg2 && ost->ct2.onoff){
+			ost->on_sec = ost->ct2.sec;
+			chg_v = 1;
+		}else if(chg && ost->ct.onoff){
+			ost->on_sec = ost->ct.sec;
+			chg_v = 1;
+
+			ost->mean = abuf_mean(ost->ab, ost->on_sec, sec);
+			chatt_set(&ost->ct2, 1);
+		}
+	}else{
+		if(chg && !ost->ct.onoff){
+			ost->off_sec = ost->ct.sec;
+			chg_v = 0;
+
+			ost->mean = -1;
+		}else if(chg2 && !ost->ct2.onoff){
+			ost->off_sec = ost->ct2.sec;
+			chg_v = 0;
+		}
+	}
+	if(chg_v >= 0) ost->v = chg_v;
+	return chg_v;
+}
diff -urN midi_prog-/pitch.h midi_prog/pitch.h
--- midi_prog-/pitch.h	Thu Aug 27 00:00:00 2015
+++ midi_prog/pitch.h	Thu Sep 10 00:00:00 2015
@@ -18,4 +18,20 @@
 		double tick_freq, double abuf_wsec);
 void pitch_add(struct pitch *p, double v);
 
+struct onoff_stat{
+	struct abuf *ab;	
+	struct chatt ct, ct2;
+	int v;
+	double on_sec;
+	double off_sec;
+
+	double thres;
+	double mean_thres;
+	double mean;
+};
+
+void onoff_stat_init(struct onoff_stat *ost, struct abuf *ab, int ac, char **av);
+int onoff_stat_add(struct onoff_stat *ost, double v, double max_v);
+int onoff_stat_add_sec(struct onoff_stat *ost, double sec, double max_v);
+
 #endif
diff -urN midi_prog-/tool.c midi_prog/tool.c
--- midi_prog-/tool.c	Wed Sep  9 00:00:00 2015
+++ midi_prog/tool.c	Thu Sep 10 00:00:00 2015
@@ -100,32 +100,24 @@
 }
 
 struct note_onoff{
-	struct chatt ct, ct2;
+	struct onoff_stat ost;
 	struct abuf ab;
 	struct pitdet *pd;
 	int note;
-	double on_sec;
 	double pre_release;
 	int cut_over_tone;
-	double peak, peak_thres;
 	int onoff;
 } note_onoff[ NOTE_N ];
 
 void
 note_onoff_init(struct note_onoff *nto, struct pitdet *pd, int note, int ac, char **av)
 {
-	double lmt_sec = opt_double("-lmt_sec", ac, av, 2.0/32);
-	chatt_init(&nto->ct, lmt_sec);
+	onoff_stat_init(&nto->ost, &nto->ab, ac, av);
 	abuf_init(&nto->ab, pd->tick_freq, 2*4*4);
 	nto->pd = pd;
 	nto->note = note;
-	nto->on_sec = -1;
 	nto->pre_release = opt_double("-pre_release", ac, av, 0);
 	nto->cut_over_tone = opt_idx("-cut_over_tone", ac, av) > 0;
-
-	chatt_init(&nto->ct2, lmt_sec);
-	nto->peak = -1;
-	nto->peak_thres = opt_double("-peak_thres", ac, av, 0.1);
 	nto->onoff = 0;
 }
 
@@ -173,45 +165,18 @@
 note_onoff_add(struct note_onoff *nto, double sec, int onoff, double v, int ch)
 {
 	double on_sec, off_sec;
-	int tick, velo;
-	int chg, chg2, chg_a = -1;
+	int tick, velo, chg_v;
 
 	abuf_add(&nto->ab, v);
 
-	chg = chatt_add(&nto->ct, sec, onoff);
-	if(nto->peak >= 0){
-		nto->peak = MAX(nto->peak, v);
-		chg2 = chatt_add(&nto->ct2, sec, v > nto->peak * nto->peak_thres);
-	}
+	chg_v = onoff_stat_add_sec(&nto->ost, sec, nto->pd->max_v);
 
-	if(!nto->onoff){
-		if(nto->peak >= 0 && chg2 && nto->ct2.onoff){
-			nto->on_sec = nto->ct2.sec;
-			chg_a = 1;
-		}else if(chg && nto->ct.onoff){
-			nto->on_sec = nto->ct.sec;
-			chg_a = 1;
-
-			nto->peak = abuf_max(&nto->ab, nto->on_sec, sec, NULL);
-			chatt_set(&nto->ct2, 1);
-		}
-	}else{
-		if(chg && !nto->ct.onoff){
-			off_sec = nto->ct.sec;
-			chg_a = 0;
-
-			nto->peak = -1;
-		}else if(chg2 && !nto->ct2.onoff){
-			off_sec = nto->ct2.sec;
-			chg_a = 0;
-		}
-	}
-	if(chg_a < 0) return;
-	if((nto->onoff = chg_a) > 0) return;
-	if(nto->on_sec < 0) return;
+	if(chg_v < 0) return;
+	if((nto->onoff = chg_v) > 0) return;
+	if(nto->ost.on_sec < 0) return;
 
-	on_sec = nto->on_sec;
-	nto->on_sec = -1;
+	on_sec = nto->ost.on_sec;
+	off_sec = nto->ost.off_sec;
 
 	if(nto->pre_release > 0){
 		double off_lmt = on_sec + 1.0 / nto->pd->tick_freq;