Begin work on AudioEffectDelayExternal...

Audio.h

 #include "effect_envelope.h"
 #include "effect_multiply.h"
 #include "effect_delay.h"
+#include "effect_delay_ext.h"
 #include "filter_biquad.h"
 #include "filter_fir.h"
 #include "filter_variable.h"

effect_delay_ext.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_ext.h"
+
+void AudioEffectDelayExternal::update(void)
+{
+	audio_block_t *block;
+	uint32_t n, channel, read_offset;
+
+	// grab incoming data and put it into the memory
+	block = receiveReadOnly();
+	if (memory_type >= AUDIO_MEMORY_UNDEFINED) {
+		// ignore input and do nothing is undefined memory type
+		release(block);
+		return;
+	}
+	if (block) {
+		if (head_offset + AUDIO_BLOCK_SAMPLES <= memory_length) {
+			// a single write is enough
+			write(head_offset, AUDIO_BLOCK_SAMPLES, block->data);
+			head_offset += AUDIO_BLOCK_SAMPLES;
+		} else {
+			// write wraps across end-of-memory
+			n = memory_length - head_offset;
+			write(head_offset, n, block->data);
+			head_offset = AUDIO_BLOCK_SAMPLES - n;
+			write(0, head_offset, block->data + n);
+		}
+		release(block);
+	} else {
+		// if no input, store zeros, so later playback will
+		// not be random garbage previously stored in memory
+		if (head_offset + AUDIO_BLOCK_SAMPLES <= memory_length) {
+			zero(head_offset, AUDIO_BLOCK_SAMPLES);
+			head_offset += AUDIO_BLOCK_SAMPLES;
+		} else {
+			n = memory_length - head_offset;
+			zero(head_offset, n);
+			head_offset = AUDIO_BLOCK_SAMPLES - n;
+			zero(0, head_offset);
+		}
+	}
+
+	// transmit the delayed outputs
+	for (channel = 0; channel < 8; channel++) {
+		if (!(activemask & (1<<channel))) continue;
+		block = allocate();
+		if (!block) continue;
+		// compute the delayed location where we read
+		if (delay_length[channel] <= head_offset) {
+			read_offset = head_offset - delay_length[channel];
+		} else {
+			read_offset = memory_length + head_offset - delay_length[channel];
+		}
+		if (read_offset + AUDIO_BLOCK_SAMPLES <= memory_length) {
+			// a single read will do it
+			read(read_offset, AUDIO_BLOCK_SAMPLES, block->data);
+		} else {
+			// read wraps across end-of-memory
+			n = memory_length - read_offset;
+			read(read_offset, n, block->data);
+			read(0, AUDIO_BLOCK_SAMPLES - n, block->data + n);
+		}
+		transmit(block, channel);
+		release(block);
+	}
+}
+
+uint32_t AudioEffectDelayExternal::allocated[2] = {0, 0};
+
+
+void AudioEffectDelayExternal::initialize(AudioEffectDelayMemoryType_t type, uint32_t samples)
+{
+	uint32_t memsize, avail;
+
+	activemask = 0;
+	head_offset = 0;
+	memory_type = type;
+	if (type == AUDIO_MEMORY_23LC1024) {
+		//memsize = 65536;
+		memsize = 8000;
+	} else if (type == AUDIO_MEMORY_MEMORYBOARD) {
+		memsize = 393216;
+	} else {
+		return;
+	}
+	avail = memsize - allocated[type];
+	if (avail < AUDIO_BLOCK_SAMPLES*2+1) {
+		memory_type = AUDIO_MEMORY_UNDEFINED;
+		return;
+	}
+	if (samples > avail) samples = avail;
+	memory_begin = allocated[type];
+	allocated[type] += samples;
+	memory_length = samples;
+	zero(0, memory_length);
+}
+
+
+static int16_t testmem[8000];
+
+void AudioEffectDelayExternal::read(uint32_t offset, uint32_t count, int16_t *data)
+{
+	while (count) { *data++ = testmem[memory_begin + offset++]; count--; }
+}
+
+void AudioEffectDelayExternal::write(uint32_t offset, uint32_t count, const int16_t *data)
+{
+	while (count) { testmem[memory_begin + offset++] = *data++; count--; }
+}
+
+void AudioEffectDelayExternal::zero(uint32_t offset, uint32_t count)
+{
+	while (count) { testmem[memory_begin + offset++] = 0; count--; }
+}
+

effect_delay_ext.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_ext_h_
+#define effect_delay_ext_h_
+#include "AudioStream.h"
+#include "utility/dspinst.h"
+
+enum AudioEffectDelayMemoryType_t {
+	AUDIO_MEMORY_23LC1024 = 0,
+	AUDIO_MEMORY_MEMORYBOARD = 1,
+	AUDIO_MEMORY_UNDEFINED = 2
+};
+
+class AudioEffectDelayExternal : public AudioStream
+{
+public:
+	AudioEffectDelayExternal() : AudioStream(1, inputQueueArray) {
+		initialize(AUDIO_MEMORY_23LC1024, 8000);
+	}
+	AudioEffectDelayExternal(AudioEffectDelayMemoryType_t type, float milliseconds=1e6)
+	  : AudioStream(1, inputQueueArray) {
+		uint32_t n = (milliseconds*(AUDIO_SAMPLE_RATE_EXACT/1000.0f))+0.5f;
+		initialize(type, n);
+	}
+
+	void delay(uint8_t channel, float milliseconds) {
+		if (channel >= 8 || memory_type >= AUDIO_MEMORY_UNDEFINED) return;
+		if (milliseconds < 0.0) milliseconds = 0.0;
+		uint32_t n = (milliseconds*(AUDIO_SAMPLE_RATE_EXACT/1000.0f))+0.5f;
+		n += AUDIO_BLOCK_SAMPLES;
+		if (n > memory_length - AUDIO_BLOCK_SAMPLES)
+			n = memory_length - AUDIO_BLOCK_SAMPLES;
+		delay_length[channel] = n;
+		uint8_t mask = activemask;
+		if (activemask == 0) AudioStartUsingSPI();
+		activemask = mask | (1<<channel);
+	}
+	void disable(uint8_t channel) {
+		if (channel >= 8) return;
+		uint8_t mask = activemask & ~(1<<channel);
+		activemask = mask;
+		if (mask == 0) AudioStopUsingSPI();
+	}
+	virtual void update(void);
+private:
+	void initialize(AudioEffectDelayMemoryType_t type, uint32_t samples);
+	void read(uint32_t address, uint32_t count, int16_t *data);
+	void write(uint32_t address, uint32_t count, const int16_t *data);
+	void zero(uint32_t address, uint32_t count);
+	uint32_t memory_begin;    // the first address in the memory we're using
+	uint32_t memory_length;   // the amount of memory we're using
+	uint32_t head_offset;     // head index (incoming) data into external memory
+	uint32_t delay_length[8]; // # of sample delay for each channel (128 = no delay)
+	uint8_t  activemask;      // which output channels are active
+	uint8_t  memory_type;     // 0=23LC1024, 1=Frank's Memoryboard
+	static uint32_t allocated[2];
+	audio_block_t *inputQueueArray[1];
+};
+
+#endif

keywords.txt

 AudioEffectEnvelope	KEYWORD2
 AudioEffectMultiply	KEYWORD2
 AudioEffectDelay	KEYWORD2
+AudioEffectDelayExternal	KEYWORD2
+AudioEffectBitcrusher	KEYWORD2
 AudioFilterBiquad	KEYWORD2
 AudioFilterFIR	KEYWORD2
 AudioFilterStateVariable	KEYWORD2
 surroundSound	KEYWORD2
 surroundSoundEnable	KEYWORD2
 calcBiquad	KEYWORD2
-
-
+sampleRate	KEYWORD2
+bits	KEYWORD2
 
 AudioMemoryUsage	KEYWORD2
 AudioMemoryUsageMax	KEYWORD2
 WAVEFORM_ARBITRARY	LITERAL1
 WAVEFORM_PULSE	LITERAL1
 
+AUDIO_MEMORY_23LC1024	LITERAL1
+AUDIO_MEMORY_MEMORYBOARD	LITERAL1