Add AudioEffectDelay

Audio.h

 #include "effect_flange.h"
 #include "effect_envelope.h"
 #include "effect_multiply.h"
+#include "effect_delay.h"
 #include "filter_biquad.h"
 #include "filter_fir.h"
 #include "input_adc.h"

effect_delay.cpp

+/* Audio Library for Teensy 3.X
+ * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
+ *
+ * Development of this audio library was funded by PJRC.COM, LLC by sales of
+ * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
+ * open source software by purchasing Teensy or other PJRC products.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice, development funding notice, and this permission
+ * notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "effect_delay.h"
+
+void AudioEffectDelay::update(void)
+{
+	audio_block_t *output;
+	uint32_t head, tail, count, channel, index, prev, offset;
+	const int16_t *src, *end;
+	int16_t *dst;
+
+	// grab incoming data and put it into the queue
+	head = headindex;
+	tail = tailindex;
+	if (++head >= DELAY_QUEUE_SIZE) head = 0;
+	if (head == tail) {
+		release(queue[tail]);
+		if (++tail >= DELAY_QUEUE_SIZE) tail = 0;
+	}
+	queue[head] = receiveReadOnly();
+	headindex = head;
+
+	// testing only.... don't allow null pointers into the queue
+	// instead, fill the empty times with blocks of zeros
+	//if (queue[head] == NULL) {
+	//	queue[head] = allocate();
+	//	if (queue[head]) {
+	//		dst = queue[head]->data;
+	//		end = dst + AUDIO_BLOCK_SAMPLES;
+	//		do {
+	//			*dst++ = 0;
+	//		} while (dst < end);
+	//	} else {
+	//		digitalWriteFast(2, HIGH);
+	//		delayMicroseconds(5);
+	//		digitalWriteFast(2, LOW);
+	//	}
+	//}
+
+	// discard unneeded blocks from the queue
+	if (head >= tail) {
+		count = head - tail;
+	} else {
+		count = DELAY_QUEUE_SIZE + head - tail;
+	}
+	if (count > maxblocks) {
+		count -= maxblocks;
+		do {
+			release(queue[tail]);
+			queue[tail] = NULL;
+			if (++tail >= DELAY_QUEUE_SIZE) tail = 0;
+		} while (--count > 0);
+	}
+	tailindex = tail;
+
+	// transmit the delayed outputs using queue data
+	for (channel = 0; channel < 8; channel++) {
+		if (!(activemask & (1<<channel))) continue;
+		index =  position[channel] / AUDIO_BLOCK_SAMPLES;
+		offset = position[channel] % AUDIO_BLOCK_SAMPLES;
+		if (head >= index) {
+			index = head - index;
+		} else {
+			index = DELAY_QUEUE_SIZE + head - index;
+		}
+		if (offset == 0) {
+			// delay falls on the block boundary
+			if (queue[index]) {
+				transmit(queue[index], channel);
+			}
+		} else {
+			// delay requires grabbing data from 2 blocks
+			output = allocate();
+			if (!output) continue;
+			dst = output->data;
+			if (index > 0) {
+				prev = index - 1;
+			} else {
+				prev = DELAY_QUEUE_SIZE-1;
+			}
+			if (queue[prev]) {
+				end = queue[prev]->data + AUDIO_BLOCK_SAMPLES;
+				src = end - offset;
+				while (src < end) {
+					*dst++ = *src++; // TODO: optimize
+				}
+			} else {
+				end = dst + offset;
+				while (dst < end) {
+					*dst++ = 0;
+				}
+			}
+			end = output->data + AUDIO_BLOCK_SAMPLES;
+			if (queue[index]) {
+				src = queue[index]->data;
+				while (dst < end) {
+					*dst++ = *src++; // TODO: optimize
+				}
+			} else {
+				while (dst < end) {
+					*dst++ = 0;
+				}
+			}
+			transmit(output, channel);
+			release(output);
+		}
+	}
+
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
+

effect_delay.h

+/* Audio Library for Teensy 3.X
+ * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
+ *
+ * Development of this audio library was funded by PJRC.COM, LLC by sales of
+ * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
+ * open source software by purchasing Teensy or other PJRC products.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice, development funding notice, and this permission
+ * notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef effect_delay_h_
+#define effect_delay_h_
+#include "AudioStream.h"
+#include "utility/dspinst.h"
+
+#define DELAY_QUEUE_SIZE  117
+
+class AudioEffectDelay : public AudioStream
+{
+public:
+	AudioEffectDelay() : AudioStream(1, inputQueueArray) {
+		activemask = 0;
+		headindex = 0;
+		tailindex = 0;
+		maxblocks = 0;
+		memset(queue, 0, sizeof(queue));
+	}
+	void delay(uint8_t channel, float milliseconds) {
+		if (channel >= 8) return;
+		if (milliseconds < 0.0) milliseconds = 0.0;
+		uint32_t n = (milliseconds*(AUDIO_SAMPLE_RATE_EXACT/1000.0))+0.5;
+		uint32_t nmax = AUDIO_BLOCK_SAMPLES * (DELAY_QUEUE_SIZE-1);
+		if (n > nmax) n = nmax;
+		uint32_t blks = (n + (AUDIO_BLOCK_SAMPLES-1)) / AUDIO_BLOCK_SAMPLES + 1;
+		if (!(activemask & (1<<channel))) {
+			// enabling a previously disabled channel
+			position[channel] = n;
+			if (blks > maxblocks) maxblocks = blks;
+			activemask |= (1<<channel);
+		} else {
+			if (n > position[channel]) {
+				// new delay is greater than previous setting
+				if (blks > maxblocks) maxblocks = blks;
+				position[channel] = n;
+			} else {
+				// new delay is less than previous setting
+				position[channel] = n;
+				recompute_maxblocks();
+			}
+		}
+	}
+	void disable(uint8_t channel) {
+		if (channel >= 8) return;
+		// diable this channel
+		activemask &= ~(1<<channel);
+		// recompute maxblocks for remaining enabled channels
+		recompute_maxblocks();
+	}
+	virtual void update(void);
+private:
+	void recompute_maxblocks(void) {
+		uint32_t max=0;
+		uint32_t channel = 0;
+		do {
+			if (activemask & (1<<channel)) {
+				uint32_t n = position[channel];
+				n = (n + (AUDIO_BLOCK_SAMPLES-1)) / AUDIO_BLOCK_SAMPLES + 1;
+				if (n > max) max = n;
+			}
+		} while(++channel < 8);
+		maxblocks = max;
+	}
+	uint8_t activemask;   // which output channels are active
+	uint8_t headindex;    // head index (incoming) data in quueu
+	uint8_t tailindex;    // tail index (outgoing) data from queue
+	uint8_t maxblocks;    // number of blocks needed in queue
+	uint16_t position[8]; // # of sample delay for each channel
+	audio_block_t *queue[DELAY_QUEUE_SIZE];
+	audio_block_t *inputQueueArray[1];
+};
+
+#endif

gui/list.html

 
 
 
+<script type="text/javascript">
+	RED.nodes.registerType('AudioEffectDelay',{
+	shortName: "delay",
+		inputs:1,
+		outputs:8,
+		category: 'effect-function',
+		color:"#E6E0F8",
+		icon: "arrow-in.png"
+	});
+</script>
+<script type="text/x-red" data-help-name="AudioEffectDelay">
+	<h3>Summary</h3>
+	<p>Delay a signal.  Up to 8 separate delay taps can be used.</p>
+	<h3>Audio Connections</h3>
+	<table class=doc align=center cellpadding=3>
+		<tr class=top><th>Port</th><th>Purpose</th></tr>
+		<tr class=odd><td align=center>In 0</td><td>Signal Input</td></tr>
+		<tr class=odd><td align=center>Out 0</td><td>Delay Tap #1</td></tr>
+		<tr class=odd><td align=center>Out 1</td><td>Delay Tap #2</td></tr>
+		<tr class=odd><td align=center>Out 2</td><td>Delay Tap #3</td></tr>
+		<tr class=odd><td align=center>Out 3</td><td>Delay Tap #4</td></tr>
+		<tr class=odd><td align=center>Out 4</td><td>Delay Tap #5</td></tr>
+		<tr class=odd><td align=center>Out 5</td><td>Delay Tap #6</td></tr>
+		<tr class=odd><td align=center>Out 6</td><td>Delay Tap #7</td></tr>
+		<tr class=odd><td align=center>Out 7</td><td>Delay Tap #8</td></tr>
+	</table>
+	<h3>Functions</h3>
+	<p class=func><span class=keyword>delay</span>(channel, milliseconds);</p>
+	<p class=desc>Set output channel (0 to 7) to delay the signals by
+		milliseconds.  The maximum delay is approx 333 ms.  The actual delay
+		is rounded to the nearest sample.  Each channel can be configured for
+		any delay.  There is no requirement to configure the "taps" in increasing
+		delay order.
+	</p>
+	<p class=func><span class=keyword>disable</span>(channel);</p>
+	<p class=desc>Disable a channel.  The output of this channel becomes
+		silent.  If this channel is the longest delay, memory usage is
+		automatically reduced to accomodate only the remaining channels used.
+	</p>
+	<h3>Notes</h3>
+	<p>Memory for the delayed signal is take from the memory pool allocated by
+		<a href="http://www.pjrc.com/teensy/td_libs_td_libs_AudioConnection.html" target="_blank">AudioMemory()</a>.
+		Each block allows about 3 milliseconds of delay, so AudioMemory
+		should be increased to allow for the longest delay tap.
+	</p>
+</script>
+<script type="text/x-red" data-template-name="AudioEffectDelay">
+	<div class="form-row">
+		<label for="node-input-name"><i class="fa fa-tag"></i> Name</label>
+		<input type="text" id="node-input-name" placeholder="Name">
+	</div>
+</script>
+
+
+
+
 <script type="text/javascript">
 	RED.nodes.registerType('AudioFilterBiquad',{
 	shortName: "biquad",

keywords.txt

 AudioEffectFlange	KEYWORD2
 AudioEffectEnvelope	KEYWORD2
 AudioEffectMultiply	KEYWORD2
+AudioEffectDelay	KEYWORD2
 AudioFilterBiquad	KEYWORD2
 AudioFilterFIR	KEYWORD2
 AudioInputAnalog	KEYWORD2