ncmixer

commit d256de1e728ec329c95868d99b047c0b820a6545
parent 45236051aa622b2050080dcc7e20a9e3c3ee4f4e
Author: lostd <lostd@2f30.org>
Date:   Wed, 16 Nov 2016 23:49:33 +0000

Add on-air state that applies fade effect on toggle

If on-air is toggled before the previous fade is finished we change
direction and complete the fade faster than the full fade.

Diffstat:
M
mixerd.c
 | 
59
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
ncmixerc.c
 | 
30
++++++++++++++++++++++++++++++
M
proto.h
 | 
8
+++++++-

3 files changed, 96 insertions(+), 1 deletion(-)
diff --git a/mixerd.c b/mixerd.c
@@ -37,12 +37,18 @@
 #define NSAMPLES 128
 #define BUFFER_TIME_MS 100
 #define TIMEO_MS 40
+#define FADE_LOW 0.25f
+#define FADE_DUR_MS 1500
 
 char *argv0;
 int debug;
 
 /* mixer state */
 float xf_pos = 0.0f; /* values in [-1.0, 1.0] */
+float fade = 1.0f; /* values in [FADE_LOW, 1.0] */
+float fadeold;
+struct timespec airtp; /* when air direction changed */
+int onair = 0;
 
 /* forward decls */
 struct input;
@@ -229,6 +235,44 @@ attenuate(struct input *in, float factor)
 	}
 }
 
+void
+applyfade(struct input *in)
+{
+	struct timespec tp;
+	float complete;
+	int durationms;
+	int deltams;
+	short *buf;
+	int i;
+
+	if ((onair && fade > FADE_LOW) || (!onair && fade < 1.0f)) {
+		clock_gettime(CLOCK_MONOTONIC, &tp);
+		deltams = (tp.tv_sec * 1000 + tp.tv_nsec / 1000000)
+		    - (airtp.tv_sec * 1000 + airtp.tv_nsec / 1000000);
+		/* fade should complete faster if it was interrupted */
+		if (onair)
+			durationms = (fadeold - FADE_LOW) * FADE_DUR_MS;
+		else
+			durationms = (1.0f - fadeold) * FADE_DUR_MS;
+		durationms /= 1.0f - FADE_LOW;
+		complete = (float)deltams / durationms;
+		fade = fadeold;
+		if (onair) {
+			fade -= (1.0f - FADE_LOW) * complete;
+			fade = MAX(fade, FADE_LOW);
+		} else {
+			fade += (1.0f - FADE_LOW) * complete;
+			fade = MIN(fade, 1.0f);
+		}
+	}
+
+	buf = (short *)in->attenuated_buf;
+	for (i = 0; i < in->nsamples; i++) {
+		*buf *= fade;
+		buf++;
+	}
+}
+
 int
 mix_master(struct output *out, struct input *in0, struct input *in1)
 {
@@ -382,6 +426,17 @@ msg_handler(int fd)
 		msg.m_output_on = outputs[msg.m_output_index].sio_hdl != NULL;
 		tx_reply = 1;
 		break;
+	case SET_AIR:
+		if (msg.m_air_on != onair) {
+			clock_gettime(CLOCK_MONOTONIC, &airtp);
+			fadeold = fade;
+		}
+		onair = msg.m_air_on;
+		break;
+	case GET_AIR:
+		msg.m_air_on = onair;
+		tx_reply = 1;
+		break;
 	default:
 		log_msg(LOG_WARNING, "unknown message type: %d", msg.type);
 		break;
@@ -525,6 +580,10 @@ loop(void)
 			attenuate(&inputs[1], 1.0f);
 		}
 
+		/* apply fade effect for on-air toggle */
+		applyfade(&inputs[0]);
+		applyfade(&inputs[1]);
+
 		/* play dat shit! */
 		for (i = 0; i < LEN(outputs); i++) {
 			out = &outputs[i];
diff --git a/ncmixerc.c b/ncmixerc.c
@@ -47,6 +47,7 @@ int in0_on;
 int in1_on;
 int out0_on;
 int out1_on;
+int air_on;
 int sock;
 
 void
@@ -195,6 +196,27 @@ get_output_on(int index, int *on)
 }
 
 void
+get_air_on(int *on)
+{
+	struct msg msg;
+
+	msg.type = GET_AIR;
+	tx_msg(&msg);
+	rx_msg(&msg);
+	*on = msg.m_air_on;
+}
+
+void
+set_air_on(int on)
+{
+	struct msg msg;
+
+	msg.type = SET_AIR;
+	msg.m_air_on = on;
+	tx_msg(&msg);
+}
+
+void
 kb_handler(void)
 {
 	int c;
@@ -268,6 +290,11 @@ kb_handler(void)
 		ch1_level = MIN(ch1_level + level_step, 1.0f);
 		set_vol_level(1, ch1_level);
 		break;
+	case CONTROL('A'):
+		get_air_on(&air_on);
+		air_on = !air_on;
+		set_air_on(air_on);
+		break;
 	case 'x':
 		curses_exit();
 		exit(0);
@@ -376,11 +403,14 @@ draw_outputs(void)
 
 	get_output_on(0, &out0_on);
 	get_output_on(1, &out1_on);
+	get_air_on(&air_on);
 
 	move(getcury(stdscr), center - strlen(" master: off") / 2);
 	printw(" master: %s\n", out0_on ? "on" : "off");
 	move(getcury(stdscr), center - strlen("monitor: off") / 2);
 	printw("monitor: %s\n", out1_on ? "on" : "off");
+	move(getcury(stdscr), center - strlen("    air: off") / 2);
+	printw("  onair: %s\n", air_on ? "on" : "off");
 }
 
 void
diff --git a/proto.h b/proto.h
@@ -6,7 +6,9 @@ enum {
 	SET_VOL,
 	GET_VOL,
 	GET_IN,
-	GET_OUT
+	GET_OUT,
+	SET_AIR,
+	GET_AIR
 };
 
 struct msg {
@@ -31,6 +33,9 @@ struct msg {
 			int index;	/* in */
 			int on;		/* out */
 		} output;
+		struct {
+			int on;		/* in/out */
+		} air;
 	} u;
 };
 #define m_xf_pos	u.xf.pos
@@ -42,3 +47,4 @@ struct msg {
 #define m_input_on	u.input.on
 #define m_output_index	u.output.index
 #define m_output_on	u.output.on
+#define m_air_on	u.air.on