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150 lines
4.2 KiB
150 lines
4.2 KiB
/* Audio Library for Teensy 3.X
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Copyright (c) 2014, Pete (El Supremo)
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Copyright (c) 2019, Holger Wirtz
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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*/
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#include <Arduino.h>
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#include <Audio.h>
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#include "limits.h"
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#include "effect_modulated_delay.h"
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#include "spline.h"
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#include "config.h"
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/******************************************************************/
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// Based on; A u d i o E f f e c t D e l a y
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// Written by Pete (El Supremo) Jan 2014
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// 140529 - change to handle mono stream - change modify() to voices()
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// 140219 - correct storage class (not static)
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// 190527 - added modulation input (by Holger Wirtz)
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boolean AudioEffectModulatedDelay::begin(short *delayline, int d_length)
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{
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#if 0
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Serial.print(F("AudioEffectModulatedDelay.begin(Chorus delay line length = "));
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Serial.print(d_length);
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Serial.println(F(")"));
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#endif
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_delayline = NULL;
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_delay_length = 0;
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_circ_idx = 0;
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if (delayline == NULL) {
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return (false);
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}
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if (d_length < 10) {
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return (false);
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}
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_delayline = delayline;
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_delay_length = _max_delay_length = d_length;
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memset(_delayline, 0, sizeof(int16_t)*_delay_length);
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return (true);
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}
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void AudioEffectModulatedDelay::update(void)
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{
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audio_block_t *block;
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audio_block_t *modulation;
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int16_t *bp;
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int16_t *mp;
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float mod_idx;
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if (_delayline == NULL)
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return;
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block = receiveWritable(0);
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modulation = receiveReadOnly(1);
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#ifdef INTERPOLATE
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int8_t j;
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float x[INTERPOLATION_WINDOW_SIZE];
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float y[INTERPOLATION_WINDOW_SIZE];
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Spline s(x, y, INTERPOLATION_WINDOW_SIZE, INTERPOLATE);
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#endif
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bp = block->data;
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mp = modulation->data;
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if (block && modulation)
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{
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for (uint16_t i = 0; i < AUDIO_BLOCK_SAMPLES; i++)
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{
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// write data into circular buffer
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if (_circ_idx >= _delay_length)
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_circ_idx = 0;
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_delayline[_circ_idx] = *bp;
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// calculate modulation index
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mod_idx = float(*mp) / SHRT_MAX * float(_delay_length / 2); // calculate an index with modulation as a float(!!!)
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#ifdef INTERPOLATE
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// get x/y values around mod_idx
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uint8_t c = 0;
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int16_t c_mod_idx = int(mod_idx + 0.5) + _circ_idx;
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int32_t avg=0;
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for (j = INTERPOLATION_WINDOW_SIZE / -2; j <= INTERPOLATION_WINDOW_SIZE / 2; j++)
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{
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int16_t jc_mod_idx = (c_mod_idx + j) % _delay_length - 1;
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if (jc_mod_idx < 0)
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y[c] = float(_delayline[_delay_length - 1 + jc_mod_idx]);
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else
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y[c] = float(_delayline[jc_mod_idx]);
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x[c] = float(c);
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avg += y[c];
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c++; // because 42 is the answer! ;-)
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}
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//*bp = int(s.value(mod_idx - int(mod_idx + 0.5)) + 0.5);
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*bp = avg / INTERPOLATION_WINDOW_SIZE;
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#else
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// No interpolation - should sound really bad...
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int16_t c_mod_idx = (int(mod_idx + 0.5) + _circ_idx) % _delay_length - 1;
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if (c_mod_idx < 0)
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*bp = _delayline[_delay_length - 1 + c_mod_idx];
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else
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*bp = _delayline[c_mod_idx];
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#endif
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bp++;
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mp++;
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_circ_idx++;
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}
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}
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if (block)
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{
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transmit(block, 0);
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release(block);
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}
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if (modulation)
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release(modulation);
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}
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void AudioEffectModulatedDelay::setDelay(float milliseconds)
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{
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_delay_length = min(AUDIO_SAMPLE_RATE * milliseconds / 500, _max_delay_length);
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}
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