132 lines
3.4 KiB
C++
Executable file
132 lines
3.4 KiB
C++
Executable file
/* Audio Library for Teensy 3.X
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* Copyright (c) 2014, Pete (El Supremo)
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*
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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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*
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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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*
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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 "effect_chorus.h"
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/******************************************************************/
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// A u d i o E f f e c t C h o r u s
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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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boolean AudioEffectChorus::begin(short *delayline,int d_length,int n_chorus)
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{
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#if 0
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Serial.print("AudioEffectChorus.begin(Chorus delay line length = ");
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Serial.print(d_length);
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Serial.print(", n_chorus = ");
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Serial.print(n_chorus);
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Serial.println(")");
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#endif
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l_delayline = NULL;
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delay_length = 0;
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l_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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if(n_chorus < 1) {
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return(false);
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}
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l_delayline = delayline;
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delay_length = d_length/2;
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num_chorus = n_chorus;
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return(true);
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}
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void AudioEffectChorus::voices(int n_chorus)
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{
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num_chorus = n_chorus;
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}
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//int last_idx = 0;
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void AudioEffectChorus::update(void)
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{
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audio_block_t *block;
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short *bp;
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int sum;
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int c_idx;
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if(l_delayline == NULL)return;
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// do passthru
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// It stores the unmodified data in the delay line so that
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// it isn't as likely to click
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if(num_chorus <= 1) {
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// Just passthrough
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block = receiveWritable(0);
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if(block) {
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bp = block->data;
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for(int i = 0;i < AUDIO_BLOCK_SAMPLES;i++) {
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l_circ_idx++;
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if(l_circ_idx >= delay_length) {
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l_circ_idx = 0;
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}
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l_delayline[l_circ_idx] = *bp++;
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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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return;
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}
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// L E F T C H A N N E L
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block = receiveWritable(0);
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if(block) {
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bp = block->data;
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uint32_t tmp = delay_length/(num_chorus - 1) - 1;
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for(int i = 0;i < AUDIO_BLOCK_SAMPLES;i++) {
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l_circ_idx++;
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if(l_circ_idx >= delay_length) {
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l_circ_idx = 0;
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}
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l_delayline[l_circ_idx] = *bp;
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sum = 0;
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c_idx = l_circ_idx;
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for(int k = 0; k < num_chorus; k++) {
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sum += l_delayline[c_idx];
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if(num_chorus > 1)c_idx -= tmp;
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if(c_idx < 0) {
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c_idx += delay_length;
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}
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}
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*bp++ = sum/num_chorus;
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}
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// transmit the block
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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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