Trying mod-delay-gain for Chorus effect.

MicroMDAEPiano.ino

@@ -28,6 +28,7 @@
 #include <MIDI.h>
 #include <EEPROM.h>
 #include <limits.h>
+#include "mod-delay-gain.h"
 #include "mdaEPiano.h"
 #ifdef USE_XFADE_DATA
 #include "mdaEPianoDataXfade.h"
@@ -59,29 +60,47 @@ AudioEffectFreeverb      freeverb_r;
 AudioEffectFreeverb      freeverb_l;
 AudioMixer4              mixer_r;
 AudioMixer4              mixer_l;
+AudioSynthWaveform delaySweep_r;
+AudioSynthWaveform envelope_r;
+AudioSynthWaveform delaySweep_l;
+AudioSynthWaveform envelope_l;
+AudioEffectModDelayGain modulatedDelay_r;
+AudioEffectModDelayGain modulatedDelay_l;
 AudioConnection          patchCord0(queue_r, peak_r);
 AudioConnection          patchCord1(queue_l, peak_l);
 AudioConnection          patchCord4(queue_r, freeverb_r);
 AudioConnection          patchCord5(queue_l, freeverb_l);
-AudioConnection          patchCord6(queue_r, 0, mixer_r, 0);
+AudioConnection          patchCord6(queue_r, modulatedDelay_r);
-AudioConnection          patchCord7(queue_l, 0, mixer_l, 0);
+AudioConnection          patchCord7(queue_l, modulatedDelay_l);
-AudioConnection          patchCord8(freeverb_r, 0, mixer_r, 1);
+AudioConnection          patchCord8(queue_r, 0, mixer_r, 0);
-AudioConnection          patchCord9(freeverb_l, 0, mixer_l, 1);
+AudioConnection          patchCord9(queue_l, 0, mixer_l, 0);
+AudioConnection          patchCord10(freeverb_r, 0, mixer_r, 1);
+AudioConnection          patchCord11(freeverb_l, 0, mixer_l, 1);
+AudioConnection          patchCord12(modulatedDelay_r, 0, mixer_r, 2);
+AudioConnection          patchCord13(modulatedDelay_l, 0, mixer_l, 2);
+AudioConnection          patchCord14(delaySweep_r, 0, modulatedDelay_r, 1);
+AudioConnection          patchCord15(delaySweep_l, 0, modulatedDelay_l, 1);
+AudioConnection          patchCord16(envelope_r, 0, modulatedDelay_r, 2);
+AudioConnection          patchCord17(envelope_l, 0, modulatedDelay_l, 2);
 #ifdef TEENSY_AUDIO_BOARD
 AudioOutputI2S           i2s1;
-AudioConnection          patchCord110(mixer_r, 0, i2s1, 0);
+AudioConnection          patchCord18(mixer_r, 0, i2s1, 0);
-AudioConnection          patchCord111(mixer_l, 0, i2s1, 1);
+AudioConnection          patchCord19(mixer_l, 0, i2s1, 1);
 AudioControlSGTL5000     sgtl5000_1;
 #else
 AudioOutputPT8211        pt8211_1;
 AudioAmplifier           volume_r;
 AudioAmplifier           volume_l;
-AudioConnection          patchCord10(mixer_r, volume_r);
+AudioConnection          patchCord18(mixer_r, volume_r);
-AudioConnection          patchCord11(mixer_l, volume_l);
+AudioConnection          patchCord19(mixer_l, volume_l);
-AudioConnection          patchCord12(volume_r, 0, pt8211_1, 1);
+AudioConnection          patchCord20(volume_r, 0, pt8211_1, 1);
-AudioConnection          patchCord13(volume_l, 0, pt8211_1, 0);
+AudioConnection          patchCord21(volume_l, 0, pt8211_1, 0);
 #endif
 
+const int32_t delayBufferLength = 4500;
+int16_t delayBuf1[delayBufferLength];
+int16_t delayBuf2[delayBufferLength];
+
 // Objects
 mdaEPiano* ep;
 
@@ -113,6 +132,7 @@ const uint16_t audio_block_time_us = 1000000 / (SAMPLE_RATE / AUDIO_BLOCK_SAMPLE
 #ifdef SHOW_CPU_LOAD_MSEC
 elapsedMillis cpu_mem_millis;
 #endif
+float modFreq = 2.0;
 
 enum MDA_EP_PARAM { DECAY, RELEASE, HARDNESS, TREBLE, PAN_TREM, LFO_RATE, VELOCITY_SENSE, STEREO, MAX_POLY, TUNE, DETUNE, OVERDRIVE };
 
@@ -127,7 +147,7 @@ void setup()
   Serial.begin(SERIAL_SPEED);
   delay(220);
 
-/*
+  /*
     // LCD display setup
     lcd.init();
     lcd.blink_off();
@@ -146,7 +166,7 @@ void setup()
     enc_val[1] = enc[1].read();
     but[0].update();
     but[1].update();
-*/
+  */
 
   // Debug output
   Serial.println(F("MicroMDAEPiano based on https://sourceforge.net/projects/mda-vst"));
@@ -183,6 +203,8 @@ void setup()
 #endif
 
   // start audio card
+  AudioNoInterrupts();
+  
   AudioMemory(AUDIO_MEM);
 
 #ifdef TEENSY_AUDIO_BOARD
@@ -223,10 +245,22 @@ void setup()
   freeverb_l.roomsize(0.2);
   freeverb_r.damping(0.5);
   freeverb_l.damping(0.5);
+
+  delaySweep_r.begin(1, modFreq, WAVEFORM_SINE);
+  delaySweep_l.begin(1, modFreq, WAVEFORM_SINE);
+  delaySweep_l.phase(180.0);
+  envelope_r.begin(1, modFreq, WAVEFORM_SINE);
+  envelope_l.begin(1, modFreq, WAVEFORM_SINE);
+  envelope_l.phase(180.0);
+
   mixer_r.gain(0, 0.7);
   mixer_l.gain(0, 0.7);
   mixer_r.gain(1, 0.3);
   mixer_l.gain(1, 0.3);
+  mixer_r.gain(2, 0.5);
+  mixer_l.gain(2, 0.5);
+
+  AudioInterrupts();
 
   Serial.println(F("<setup end>"));
 

mod-delay-gain.cpp

@@ -0,0 +1,141 @@
+/* Modulated delay line
+
+   Inspired by;
+   http://musicdsp.org/showArchiveComment.php?ArchiveID=154
+
+   But details changed for Teensy Audio.
+   No feedback within the class, just done externally
+   so we can add filters and stuff to the loop.
+
+   Delay time is a signal input to the block, and functions from 0 to 0x7fff,
+   scaling the delay time accordingly.
+*/
+/*
+   Copyright (c) 2016, Byron Jacquot, SparkFun Electronics
+   SparkFun code, firmware, and software is released under
+   the MIT License(http://opensource.org/licenses/MIT).
+
+   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 "mod-delay-gain.h"
+
+#define INTERPOLATE (1)
+
+void AudioEffectModDelayGain::update(void)
+{
+  audio_block_t *audioblock, *controlblockDelay, *controlblockGain;
+  int16_t *data, *end, *ctrlDelay, *ctrlGain;
+
+  int32_t extract_index;
+  int32_t temp;
+
+#ifdef INTERPOLATE
+  int32_t interp_delta;
+  int32_t next;
+  int16_t calc;
+#endif
+
+  if (buffer_length == 0)
+    return;
+
+  audioblock = receiveWritable(0);
+  if (!audioblock) return;
+
+  controlblockDelay = receiveReadOnly(1);
+  if (!controlblockDelay) {
+    release(audioblock);
+    return;
+  }
+
+  controlblockGain = receiveReadOnly(2);
+  if (!controlblockGain) {
+    release(audioblock);
+    release(controlblockDelay);
+    return;
+  }
+
+  data = audioblock->data;
+  end = audioblock->data + AUDIO_BLOCK_SAMPLES;
+
+  ctrlDelay = controlblockDelay->data;
+
+  ctrlGain = controlblockGain->data;
+
+  do
+  {
+    delayline_p[insert_index] = *data;
+    insert_index++;
+    if (insert_index >= buffer_length)
+    {
+      insert_index = 0;
+    }
+
+#ifdef INTERPOLATE
+    //
+    interp_delta =  (buffer_length * (*ctrlDelay));
+    delay_delta = interp_delta >> 15;   // MSB's for delay len
+    interp_delta &= 0x7fff;             //LSBs for interp distance
+#else
+    delay_delta = (buffer_length * (*ctrlDelay)) >> 15;
+#endif
+
+    extract_index = insert_index - delay_delta;
+
+    if (extract_index < 0)
+    {
+      extract_index = buffer_length + extract_index;
+    }
+
+#ifdef INTERPOLATE
+    // Use the fractional part to interpolate between samples
+    next = extract_index + 1;
+    if (next >= buffer_length)
+    {
+      next = 0;
+    }
+
+    calc = delayline_p[next] -  delayline_p[extract_index];
+
+    calc = (calc * interp_delta ) >> 15;
+    calc += delayline_p[extract_index];
+
+    //*data = calc;
+    temp = (int32_t)calc * (*ctrlGain);
+    *data = temp >> 15;
+#else
+    //data = delayline_p[extract_index];
+    temp = (int32_t)delayline_p[extract_index] * (*ctrlGain);
+    *data = temp >> 15;
+#endif
+
+    data++;
+    ctrlDelay++;
+    ctrlGain++;
+  } while (data < end);
+  transmit(audioblock);
+  release(audioblock);
+  release(controlblockDelay);
+  release(controlblockGain);
+}
+
+

mod-delay-gain.h

@@ -0,0 +1,93 @@
+/* Modulated delay line
+
+   Inspired by;
+   http://musicdsp.org/showArchiveComment.php?ArchiveID=154
+
+   But details changed for Teensy Audio.
+   No feedback within the class, just done externally
+   so we can add filters and stuff to the loop.
+
+   Delay time is a signal input to the block, and functions from 0 to 0x7fff,
+   scaling the delay time accordingly.
+*/
+/*
+   Copyright (c) 2016, Byron Jacquot, SparkFun Electronics
+   SparkFun code, firmware, and software is released under
+   the MIT License(http://opensource.org/licenses/MIT).
+
+   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.
+
+
+*/
+
+/* from https://forum.pjrc.com/threads/46793-Anyone-Doing-Pitch-Shifting */
+
+#pragma once
+
+#ifndef _mod_delay_h_
+#define _mod_delay_h_
+
+
+#include "AudioStream.h"
+#include <Arduino.h>
+
+class AudioEffectModDelayGain: public AudioStream
+{
+  public:
+    AudioEffectModDelayGain   (void) : AudioStream(3, inputQueueArray)
+    {
+      buffer_length = 0;
+    }
+
+    virtual void update(void);
+
+    // Set the parameters
+    void setbuf(int32_t delay_len, int16_t* delay_buf )
+    {
+      delayline_p = delay_buf;
+      insert_index = 0;
+      buffer_length = delay_len;
+
+      for (int32_t i = 0; i < buffer_length; i++)
+      {
+        delayline_p[i] = 0;
+      }
+    };
+
+    void inspect(void)
+    {
+      Serial.print(insert_index, HEX);
+      Serial.print(' ');
+      Serial.print(delay_delta, HEX);
+      Serial.print(' ');
+      Serial.println(buffer_length, HEX);
+
+    };
+
+  private:
+    audio_block_t *inputQueueArray[3];
+
+    int16_t *delayline_p;
+
+    int32_t insert_index;
+    int32_t buffer_length;
+    int32_t delay_delta;
+};
+
+#endif