diff -urN midi_prog-/buf.c midi_prog/buf.c
--- midi_prog-/buf.c	Wed Aug 26 00:34:39 2015
+++ midi_prog/buf.c	Thu Aug 27 00:00:00 2015
@@ -305,3 +305,15 @@
 	if(ab->max_v < v) ab->max_v = v;
 	ab->sum += v - ov;
 }
+
+double
+abuf_mean(struct abuf *ab, double from_sec, double to_sec)
+{
+	int from_i = (int) tbuf_sec_to_sridx(&ab->tb, from_sec);
+	int to_i = (int) tbuf_sec_to_sridx(&ab->tb, to_sec);
+	int i;
+	double sum = 0;
+	if(from_i >= to_i) return 0;
+	for(i=from_i; i<to_i; i++) sum += rbuf_get_dbl(&ab->tb.rb, i);
+	return sum / (to_i - from_i);
+}
diff -urN midi_prog-/buf.h midi_prog/buf.h
--- midi_prog-/buf.h	Wed Aug 26 00:34:19 2015
+++ midi_prog/buf.h	Thu Aug 27 00:00:00 2015
@@ -85,5 +85,6 @@
 
 void abuf_init(struct abuf *ab, double smp_freq, double wsec);
 void abuf_add(struct abuf *ab, double v);
+double abuf_mean(struct abuf *ab, double from_sec, double to_sec);
 
 #endif
diff -urN midi_prog-/pitch.c midi_prog/pitch.c
--- midi_prog-/pitch.c	Wed Aug 12 00:00:00 2015
+++ midi_prog/pitch.c	Thu Aug 27 00:00:00 2015
@@ -46,12 +46,12 @@
 
 void
 pitch_init(struct pitch *p, double smp_freq, double freq, int wn,
-	   double abuf_wsec)
+	   double tick_freq, double abuf_wsec)
 {
 	p->freq = freq;
 	p->wn = wn;
 	sbuf_init(&p->sb, smp_freq, pitch_wsec(p->freq, wn));
-	abuf_init(&p->ab, 2*96, abuf_wsec);
+	abuf_init(&p->ab, tick_freq, abuf_wsec);
 }	    
 
 void
diff -urN midi_prog-/pitch.h midi_prog/pitch.h
--- midi_prog-/pitch.h	Wed Aug 12 00:00:00 2015
+++ midi_prog/pitch.h	Thu Aug 27 00:00:00 2015
@@ -15,7 +15,7 @@
 double pitch_freq(double wsec, double wn);
 
 void pitch_init(struct pitch *p, double smp_freq, double freq, int wn,
-		double abuf_wsec);
+		double tick_freq, double abuf_wsec);
 void pitch_add(struct pitch *p, double v);
 
 #endif
diff -urN midi_prog-/pitdet.c midi_prog/pitdet.c
--- midi_prog-/pitdet.c	Wed Aug 26 01:00:00 2015
+++ midi_prog/pitdet.c	Thu Aug 27 00:00:00 2015
@@ -14,7 +14,7 @@
 
 void
 pitdet_init(struct pitdet *pd, double smp_freq, int adj_cent,
-	    int div, double abuf_wsec, double thres)
+	    int div, double tick_freq, double abuf_wsec, double thres)
 {
 	int j;
 
@@ -30,7 +30,7 @@
 		double next_freq = pitdet_note_to_freq(pd, next_note);
 		int wn = (int) pitch_wn(freq, next_freq);
 
-		pitch_init(&pd->arr[j], smp_freq, freq, wn, abuf_wsec);
+		pitch_init(&pd->arr[j], smp_freq, freq, wn, tick_freq, abuf_wsec);
 	}
 
 	pd->oldest.sec = -1;
diff -urN midi_prog-/pitdet.h midi_prog/pitdet.h
--- midi_prog-/pitdet.h	Tue Aug 25 00:00:00 2015
+++ midi_prog/pitdet.h	Thu Aug 27 12:53:34 2015
@@ -27,7 +27,7 @@
 double pitdet_freq_to_note(struct pitdet *pd, double freq);
 
 void pitdet_init(struct pitdet *pd, double smp_freq, int adj_cent,
-		 int div, double abuf_wsec, double thres);
+		 int div, double tick_freq, double abuf_wsec, double thres);
 
 void pitdet_add(struct pitdet *pd, double v);
 
diff -urN midi_prog-/tool.c midi_prog/tool.c
--- midi_prog-/tool.c	Tue Aug 25 00:00:00 2015
+++ midi_prog/tool.c	Thu Aug 27 00:00:00 2015
@@ -80,7 +80,7 @@
 struct chatt{
 	double lmt_sec, sec, chg_try_sec;
 	int onoff;
-} chatt[ NOTE_N ];
+};
 
 void
 chatt_init(struct chatt *ct, double lmt_sec)
@@ -112,25 +112,80 @@
 	return 1;
 }
 
+struct note_onoff{
+	struct chatt ct;
+	struct abuf ab;
+	struct pitdet *pd;
+	int note;
+	double on_sec;
+} note_onoff[ NOTE_N ];
+
+void
+note_onoff_init(struct note_onoff *nto, double lmt_sec, double tick_freq, struct pitdet *pd, int note)
+{
+	chatt_init(&nto->ct, lmt_sec);
+	abuf_init(&nto->ab, tick_freq, 2*4*4);
+	nto->pd = pd;
+	nto->note = note;
+	nto->on_sec = -1;
+}
+
+void
+note_onoff_add(struct note_onoff *nto, double sec, int onoff, double v, int ch)
+{
+	double on_sec, off_sec;
+	int tick, velo;
+
+	abuf_add(&nto->ab, v);
+
+	if(!chatt_add(&nto->ct, sec, onoff)) return;
+
+	if(nto->ct.onoff){
+		nto->on_sec = nto->ct.sec;
+		return;
+	}
+
+	if(nto->on_sec < 0) return;
+
+	on_sec = nto->on_sec;
+	off_sec = nto->ct.sec;
+	nto->on_sec = -1;
+
+	v = abuf_mean(&nto->ab, on_sec, off_sec);
+	
+	velo = (int)(128 * v / nto->pd->max_v);
+	if(velo <= 0) return;
+	if(velo > 127) velo = 127;
+
+	tick = pitdet_sec_to_tick(nto->pd, on_sec);
+	printf("abs=%08d %s ch=%d note=%d velo=%d\n",
+	       tick, "on ", ch, nto->note, velo);
+	
+	tick = pitdet_sec_to_tick(nto->pd, off_sec);
+	printf("abs=%08d %s ch=%d note=%d velo=%d\n",
+	       tick, "off", ch, nto->note, velo);
+
+	fflush(stdout);
+}
+
 static void
 midi_out(struct pitdet *pd)
 {
 	double sec = pd->oldest.sec;
 	int i, k;
-	int tick, ch = 0, velo = 100;
+	int ch = 0;
 
 	for(i=0; i<NOTE_N; i++){
 		int onoff = 0;
+		double sum = 0, v;
 		for(k=0; k<pd->div; k++){
 			int j = i * pd->div + k;
-			onoff |= pitdet_onoff(pd, sec, j, NULL);
+			int o = pitdet_onoff(pd, sec, j, &v);
+			onoff |= o;
+			if(o) sum += v;
 		}
-		if(!chatt_add(&chatt[i], sec, onoff)) continue;
-
-		tick = pitdet_sec_to_tick(pd, chatt[i].sec);
-		printf("abs=%08d %s ch=%d note=%d velo=%d\n",
-		       tick, chatt[i].onoff ? "on " : "off", ch, i, velo);
-		fflush(stdout);
+		v = sum;
+		note_onoff_add(&note_onoff[i], sec, onoff, v, ch);
 	}
 }
 
@@ -145,16 +200,18 @@
 	int adj_cent = opt_int("-adj_cent", ac, av, 0);
 	int div = opt_int("-div", ac, av, 1);
 	double abuf_wsec = opt_double("-abuf_wsec", ac, av, 2.5);
+	double tick_freq = opt_double("-tick_freq", ac, av, 2*96);
 	int show = opt_idx("-show", ac, av) > 0;
 	int midi = opt_idx("-midi", ac, av) > 0;
+	int abuf_wsec_chk = opt_idx("-abuf_wsec_chk", ac, av) > 0;
 	double lmt_sec = opt_double("-lmt_sec", ac, av, 2.0/32);
 	double thres = opt_double("-thres", ac, av, 0.1);
 	int sec, s;
 
-	for(i=0; i<NOTE_N; i++) chatt_init(&chatt[i], lmt_sec);
-
 	in_init(&in, ac, av);
-	pitdet_init(&pd, in.smp_freq, adj_cent, div, abuf_wsec, thres);
+	pitdet_init(&pd, in.smp_freq, adj_cent, div, tick_freq, abuf_wsec, thres);
+
+	for(i=0; i<NOTE_N; i++) note_onoff_init(&note_onoff[i], lmt_sec, tick_freq, &pd, i);
 
 	while(in_do_mono(&in, &v) != EOF){
 		pitdet_add(&pd, v);
@@ -169,6 +226,10 @@
 
 		if(show) show_spectre(&pd, ac, av);
 		if(midi) midi_out(&pd);
+
+		if(abuf_wsec_chk && pd.oldest.sec >= pd.newest.sec){
+			fprintf(stderr, "%f >= %f\n", pd.oldest.sec, pd.newest.sec);
+		}
 	}
 	return 0;
 }