Add AudioEffectFade object

Audio.cpp

 
 
 
+/******************************************************************/
+
+
+extern "C" {
+extern const int16_t fader_table[256];
+};
+
+
+void AudioEffectFade::update(void)
+{
+	audio_block_t *block;
+	uint32_t i, pos, inc, index, scale;
+	int32_t val1, val2, val, sample;
+	uint8_t dir;
+
+	pos = position;
+	if (pos == 0) {
+		// output is silent
+		block = receiveReadOnly();
+		if (block) release(block);
+		return;
+	} else if (pos == 0xFFFFFFFF) {
+		// output is 100%
+		block = receiveReadOnly();
+		if (!block) return;
+		transmit(block);
+		release(block);
+		return;
+	}
+	block = receiveWritable();
+	if (!block) return;
+	inc = rate;
+	dir = direction;
+	for (i=0; i < AUDIO_BLOCK_SAMPLES; i++) {
+		index = pos >> 24;
+		val1 = fader_table[index];
+		val2 = fader_table[index+1];
+		scale = (pos >> 8) & 0xFFFF;
+		val2 *= scale;
+		val1 *= 0x10000 - scale;
+		val = (val1 + val2) >> 16;
+		sample = block->data[i];
+		sample = (sample * val) >> 15;
+		block->data[i] = sample;
+		if (dir > 0) {
+			// output is increasing
+			if (inc < 0xFFFFFFFF - pos) pos += inc;
+			else pos = 0xFFFFFFFF;
+		} else {
+			// output is decreasing
+			if (inc < pos) pos -= inc;
+			else pos = 0;
+		}
+	}
+	position = pos;
+	transmit(block);
+	release(block);
+}
+
+void AudioEffectFade::fadeBegin(uint32_t newrate, uint8_t dir)
+{
+	__disable_irq();
+	uint32_t pos = position;
+	if (pos == 0) position = 1;
+	else if (pos == 0xFFFFFFFF) position = 0xFFFFFFFE;
+	rate = newrate;
+	direction = dir;
+	__enable_irq();
+}
+
+
 
 /******************************************************************/
 
 
 bool AudioControlSGTL5000::enable(void)
 {
-	unsigned int n;
+	//unsigned int n;
 
 	muted = true;
 	Wire.begin();
 	delay(5);
-	Serial.print("chip ID = ");
-	delay(5);
-	n = read(CHIP_ID);
-	Serial.println(n, HEX);
+	//Serial.print("chip ID = ");
+	//delay(5);
+	//n = read(CHIP_ID);
+	//Serial.println(n, HEX);
 
 	write(CHIP_ANA_POWER, 0x4060);  // VDDD is externally driven with 1.8V
 	write(CHIP_LINREG_CTRL, 0x006C);  // VDDA & VDDIO both over 3.1V

Audio.h

 
 
 
-
+class AudioEffectFade : public AudioStream
+{
+public:
+	AudioEffectFade(void)
+	  : AudioStream(1, inputQueueArray), position(0xFFFFFFFF) {}
+	void fadeIn(uint32_t milliseconds) {
+		uint32_t samples = (uint32_t)(milliseconds * 441u + 5u) / 10u;
+		//Serial.printf("fadeIn, %u samples\n", samples);
+		fadeBegin(0xFFFFFFFFu / samples, 1);
+	}
+	void fadeOut(uint32_t milliseconds) {
+		uint32_t samples = (uint32_t)(milliseconds * 441u + 5u) / 10u;
+		//Serial.printf("fadeOut, %u samples\n", samples);
+		fadeBegin(0xFFFFFFFFu / samples, 0);
+	}
+	virtual void update(void);
+private:
+	void fadeBegin(uint32_t newrate, uint8_t dir);
+	uint32_t position; // 0 = off, 0xFFFFFFFF = on
+	uint32_t rate;
+	uint8_t direction; // 0 = fading out, 1 = fading in
+	audio_block_t *inputQueueArray[1];
+};
 
 
 

waveforms.c

 
 
 
-
+const int16_t fader_table[257] = {
+    0,    1,    4,   11,   19,   30,   44,   60,   78,   99,
+  123,  149,  177,  208,  241,  276,  314,  355,  398,  443,
+  490,  541,  593,  648,  705,  764,  826,  891,  957, 1026,
+ 1097, 1171, 1247, 1325, 1405, 1488, 1572, 1660, 1749, 1840,
+ 1934, 2030, 2128, 2228, 2330, 2435, 2541, 2650, 2761, 2873,
+ 2988, 3105, 3224, 3344, 3467, 3592, 3718, 3847, 3977, 4109,
+ 4243, 4379, 4517, 4657, 4798, 4941, 5086, 5232, 5380, 5530,
+ 5682, 5835, 5989, 6145, 6303, 6462, 6623, 6785, 6949, 7114,
+ 7281, 7448, 7618, 7788, 7960, 8133, 8307, 8483, 8660, 8838,
+ 9017, 9197, 9378, 9560, 9743, 9928,10113,10299,10486,10674,
+10863,11053,11244,11435,11627,11820,12013,12207,12402,12597,
+12793,12989,13186,13384,13582,13780,13979,14178,14377,14577,
+14777,14977,15177,15378,15579,15780,15981,16182,16383,16584,
+16785,16986,17187,17387,17588,17788,17989,18188,18388,18588,
+18787,18985,19184,19382,19579,19776,19972,20168,20364,20558,
+20752,20946,21139,21331,21522,21712,21902,22091,22279,22466,
+22652,22838,23022,23205,23388,23569,23749,23928,24106,24283,
+24458,24633,24806,24977,25148,25317,25485,25651,25817,25980,
+26142,26303,26463,26620,26776,26931,27084,27236,27385,27534,
+27680,27825,27968,28109,28249,28386,28522,28656,28789,28919,
+29048,29174,29299,29422,29542,29661,29778,29893,30006,30116,
+30225,30331,30436,30538,30638,30736,30832,30926,31017,31107,
+31194,31279,31361,31442,31520,31596,31669,31740,31809,31876,
+31940,32002,32062,32119,32174,32226,32276,32324,32369,32412,
+32452,32490,32526,32559,32590,32618,32644,32667,32688,32707,
+32723,32737,32748,32756,32763,32766,32767
+};
+#if 0
+#! /usr/bin/perl
+print "const int16_t fader_table[257] = {\n";
+$len = 256;
+for ($i=0; $i < $len+1; $i++) {
+        $a = cos(3.14149 * $i / $len);
+        $in = (1 - $a) / 2;
+        $d = $in * 32768;
+        $d = 32767 if $d >= 32767.5;
+        printf "%5d", $d;
+        print "," if ($i < $len);
+        print "\n" if ($i % 10) == 9;
+}
+print "\n};\n";
+#endif