Add AudioEffectGranular, untested (Bleep Labs)

Audio.h

 #include "effect_reverb.h"
 #include "effect_freeverb.h"
 #include "effect_waveshaper.h"
+#include "effect_granular.h"
 #include "filter_biquad.h"
 #include "filter_fir.h"
 #include "filter_variable.h"

effect_granular.cpp

+/*
+ * Copyright (c) 2018 John-Michael Reed
+ * bleeplabs.com
+ *
+ * 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 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 <Arduino.h>
+#include "effect_granular.h"
+
+void AudioEffectGranular::begin(int16_t *sample_bank_def, int16_t max_len_def)
+{
+	sample_req=1;
+	length(max_len_def - 1);
+	sample_bank = sample_bank_def;
+}
+
+void AudioEffectGranular::length(int16_t max_len_def)
+{
+	if (max_len_def < 100) {
+		max_sample_len = 100;
+		glitch_len = max_sample_len/3;
+	} else {
+		max_sample_len = (max_len_def - 1);
+		glitch_len = max_sample_len/3;
+	}
+}
+
+
+void AudioEffectGranular::freeze(int16_t activate, int16_t playpack_rate_def, int16_t freeze_length_def)
+{
+	if (activate==1) {
+		grain_mode = 1;
+	}
+	if (activate==0) {
+		grain_mode = 0;
+	}
+	rate(playpack_rate_def);
+	if (freeze_length_def < 50) {
+		freeze_len = 50;
+	}
+	if (freeze_length_def>=max_sample_len) {
+		freeze_len = max_sample_len;
+	}
+	if (freeze_length_def>=50 && freeze_length_def<max_sample_len) {
+		freeze_len = freeze_length_def;
+	}
+}
+
+void AudioEffectGranular::shift(int16_t activate, int16_t playpack_rate_def, int16_t grain_length_def)
+{
+	if (activate == 1) {
+		grain_mode = 2;
+	}
+	if (activate == 0) {
+		grain_mode = 3;
+	}
+	rate(playpack_rate_def);
+	if (allow_len_change == 1 ) {
+		//  Serial.println("aL");
+		length(grain_length_def);
+	}
+}
+
+
+void AudioEffectGranular::rate(int16_t playpack_rate_def)
+{
+	playpack_rate = playpack_rate_def;
+}
+
+
+void AudioEffectGranular::update(void)
+{
+	audio_block_t *block;
+
+	if (sample_bank == NULL) return;
+
+	block = receiveWritable(0);
+	if (!block) return;
+
+	if (grain_mode == 3) {
+		//through
+		/*
+		for (int i = 0; i < AUDIO_BLOCK_SAMPLES; i++) {
+			write_head++;
+			if (write_head >= max_sample_len) {
+				write_head = 0;
+			}
+			sample_bank[write_head] = block->data[i];
+		}
+		*/
+	}
+
+	if (grain_mode == 0) {
+		//capture audio but dosen't output
+		//this needs to be happening at all times if you want to
+		// use grain_mode = 1, the simple "freeze" sampler.
+		for (int i = 0; i < AUDIO_BLOCK_SAMPLES; i++) {
+			write_head++;
+
+			if (write_head >= max_sample_len) {
+				write_head = 0;
+			}
+			sample_bank[write_head] = block->data[i];
+		}
+	}
+
+
+	if (grain_mode == 1) {
+		//when activated the last 
+		for (int j = 0; j < AUDIO_BLOCK_SAMPLES; j++) {
+			if (playpack_rate >= 0) {
+				accumulator += playpack_rate;
+				read_head = accumulator >> 9;
+			}
+			if (read_head >= freeze_len) {
+				accumulator = 0;
+				read_head -= max_sample_len;
+			}
+			block->data[j] = sample_bank[read_head];
+		}
+	}
+
+	if (grain_mode == 2) { 
+		//GLITCH SHIFT
+		//basic granular synth thingy 
+		// the shorter the sample the max_sample_len the more tonal it is.
+		// Longer it has more definition.  It's a bit roboty either way which
+		// is obv great and good enough for noise music.
+
+		for (int k = 0; k < AUDIO_BLOCK_SAMPLES; k++) {
+			int16_t current_input = block->data[k];
+			//we only want to start recodeing when the audio is crossing zero to minimize pops
+			if ((current_input<0 && prev_input>0)) {
+				zero_cross_down=1;
+			} else {
+				zero_cross_down=0;
+			}
+
+			prev_input=current_input;
+
+			if (zero_cross_down == 1 && sample_req == 1) {
+				write_en=1;
+			}
+			if (write_en==1) {
+				sample_req=0;
+				allow_len_change=1; //reduces noise by not allowing the length to
+						// change after the sample has been recored.
+						// kind of not too much though 
+				if (write_head >= glitch_len) {
+					glitch_cross_len=glitch_len;
+					write_head = 0;
+					sample_loaded = 1;
+					write_en=0;
+					allow_len_change=0; 
+				}
+				sample_bank[write_head] = block->data[k];
+				write_head++;
+			}
+
+			if (sample_loaded == 1) {
+				//move it to the middle third of the bank. 
+				//3 "seperate" banks are used
+				float fade_len=20.00;
+				int16_t m2=fade_len;
+
+				for (int m = 0; m < 2; m++) {
+					// I'm off by one somewhere? why is there a tick at the
+					// beginning of this only when it's combined with the
+					// fade out???? ooor am i osbserving that incorrectly
+					// either wait it works enough
+					sample_bank[m + glitch_len] = 0;    
+				}
+
+				for (int m = 2; m < glitch_len-m2; m++) {
+					sample_bank[m + glitch_len] = sample_bank[m];
+				}
+
+				for (int m = glitch_len-m2; m < glitch_len; m++) {
+					// fade out the end. You can just make fadet=0
+					// but it's a little too daleky 
+					float fadet=sample_bank[m]*(m2/fade_len);
+					sample_bank[m + glitch_len] = (int16_t)fadet;
+					m2--;
+				}
+				sample_loaded = 0;
+				sample_req=1;
+			}
+
+			accumulator += playpack_rate;
+			read_head = (accumulator >> 9);
+  
+			if (read_head >= glitch_len) {
+				read_head -= (glitch_len);
+				accumulator=0;
+
+				for (int m = 0; m < glitch_len; m++) {
+					sample_bank[m + (glitch_len*2)] = sample_bank[m+glitch_len];
+					//  sample_bank[m + (glitch_len*2)] = (m%20)*1000;
+				}
+			}
+			block->data[k] = sample_bank[read_head+(glitch_len*2)];
+		}
+	}
+	transmit(block);
+	release(block);
+}
+
+
+
+

effect_granular.h

+/*
+ * Copyright (c) 2018 John-Michael Reed
+ * bleeplabs.com
+ *
+ * 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 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 "AudioStream.h"
+
+class AudioEffectGranular : public AudioStream
+{
+public:
+	AudioEffectGranular(void): AudioStream(1,inputQueueArray) { }
+	void begin(int16_t *sample_bank_def,int16_t max_len_def);
+	void length(int16_t max_len_def);
+	void rate(int16_t playpack_rate_def);
+	void freeze(int16_t activate,int16_t playpack_rate_def,int16_t grain_length_def);
+	void shift(int16_t activate,int16_t playpack_rate_def,int16_t grain_length_def);
+	virtual void update(void);
+private:
+	audio_block_t *inputQueueArray[1];
+	int16_t *sample_bank;
+	int16_t max_sample_len;
+	int16_t write_head;
+	int16_t read_head;
+	int16_t grain_mode;
+	int16_t freeze_len;
+	int16_t allow_len_change;
+	int16_t playback_rate;
+	int16_t capture_trigger;
+	int16_t capture_index;
+	int16_t current_mode;
+	int16_t playpack_rate;
+	int32_t accumulator;
+	int32_t play_index;
+	int32_t increment;
+	int16_t sample_loaded;
+	int16_t prev_input;
+	int16_t zero_cross_up;
+	int16_t zero_cross_down;
+	int16_t sample_trigger;
+	int16_t write_en;
+	int16_t glitch_cross_len;
+	int16_t load_req;
+	int16_t glitch_len;
+	int16_t glitch_min_len;
+	int16_t sample_req;
+};
+