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134 lines
4.0 KiB
134 lines
4.0 KiB
/* Audio Library for Teensy 3.X
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Copyright (c) 2014, Pete (El Supremo)
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Copyright (c) 2019-2020, 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 "arm_math.h"
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#include "effect_modulated_delay.h"
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#include "config.h"
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extern config_t configuration;
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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, uint16_t d_length)
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{
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#if 0
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Serial.print(F("AudioEffectModulatedDelay.begin(modulated-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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_cb_index = 0;
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_delay_offset = 0;
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if (delayline == NULL)
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return (false);
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if (d_length < 10)
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return (false);
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_delayline = delayline;
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_delay_length = d_length;
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memset(_delayline, 0, _delay_length * sizeof(int16_t));
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_delay_offset = _delay_length >> 1 ;
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return (true);
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}
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uint16_t AudioEffectModulatedDelay::get_delay_length(void)
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{
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return (_delay_length);
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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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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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if (block && modulation)
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{
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int16_t *bp;
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int16_t cb_mod_index_neighbor;
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float *mp;
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float mod_index;
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float mod_number;
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float mod_fraction;
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float modulation_f32[AUDIO_BLOCK_SAMPLES];
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bp = block->data;
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arm_q15_to_float(modulation->data, modulation_f32, AUDIO_BLOCK_SAMPLES);
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mp = modulation_f32;
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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 (delayline)
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if (_cb_index >= _delay_length)
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_cb_index = 0;
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_delayline[_cb_index] = *bp;
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// calculate the modulation-index as a floating point number for interpolation
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mod_index = *mp * _delay_offset;
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mod_fraction = modff(mod_index, &mod_number); // split float of mod_index into integer (= mod_number) and fraction part
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// calculate modulation index into circular buffer
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cb_mod_index = _cb_index - (_delay_offset + mod_number);
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if (cb_mod_index < 0) // check for negative offsets and correct them
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cb_mod_index += _delay_length;
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if (cb_mod_index == _delay_length - 1)
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cb_mod_index_neighbor = 0;
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else
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cb_mod_index_neighbor = cb_mod_index + 1;
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*bp = round(float(_delayline[cb_mod_index]) * mod_fraction + float(_delayline[cb_mod_index_neighbor]) * (1.0 - mod_fraction));
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// push the pointers forward
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bp++; // next audio data
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mp++; // next modulation data
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_cb_index++; // next circular buffer index
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}
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}
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if (modulation)
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release(modulation);
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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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}
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