139 lines
3.9 KiB
C++
139 lines
3.9 KiB
C++
/* Audio Library for Teensy 3.X
|
|
* Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
|
|
*
|
|
* Development of this audio library was funded by PJRC.COM, LLC by sales of
|
|
* Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop
|
|
* open source software by purchasing Teensy or other PJRC products.
|
|
*
|
|
* 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 <Arduino.h>
|
|
#include "effect_delay.h"
|
|
|
|
void AudioEffectDelay::update(void)
|
|
{
|
|
audio_block_t *output;
|
|
uint32_t head, tail, count, channel, index, prev, offset;
|
|
const int16_t *src, *end;
|
|
int16_t *dst;
|
|
|
|
// grab incoming data and put it into the queue
|
|
head = headindex;
|
|
tail = tailindex;
|
|
if (++head >= DELAY_QUEUE_SIZE) head = 0;
|
|
if (head == tail) {
|
|
if (queue[tail] != NULL) release(queue[tail]);
|
|
if (++tail >= DELAY_QUEUE_SIZE) tail = 0;
|
|
}
|
|
queue[head] = receiveReadOnly();
|
|
headindex = head;
|
|
|
|
// testing only.... don't allow null pointers into the queue
|
|
// instead, fill the empty times with blocks of zeros
|
|
//if (queue[head] == NULL) {
|
|
// queue[head] = allocate();
|
|
// if (queue[head]) {
|
|
// dst = queue[head]->data;
|
|
// end = dst + AUDIO_BLOCK_SAMPLES;
|
|
// do {
|
|
// *dst++ = 0;
|
|
// } while (dst < end);
|
|
// } else {
|
|
// digitalWriteFast(2, HIGH);
|
|
// delayMicroseconds(5);
|
|
// digitalWriteFast(2, LOW);
|
|
// }
|
|
//}
|
|
|
|
// discard unneeded blocks from the queue
|
|
if (head >= tail) {
|
|
count = head - tail;
|
|
} else {
|
|
count = DELAY_QUEUE_SIZE + head - tail;
|
|
}
|
|
if (count > maxblocks) {
|
|
count -= maxblocks;
|
|
do {
|
|
if (queue[tail] != NULL) {
|
|
release(queue[tail]);
|
|
queue[tail] = NULL;
|
|
}
|
|
if (++tail >= DELAY_QUEUE_SIZE) tail = 0;
|
|
} while (--count > 0);
|
|
}
|
|
tailindex = tail;
|
|
|
|
// transmit the delayed outputs using queue data
|
|
for (channel = 0; channel < 8; channel++) {
|
|
if (!(activemask & (1<<channel))) continue;
|
|
index = position[channel] / AUDIO_BLOCK_SAMPLES;
|
|
offset = position[channel] % AUDIO_BLOCK_SAMPLES;
|
|
if (head >= index) {
|
|
index = head - index;
|
|
} else {
|
|
index = DELAY_QUEUE_SIZE + head - index;
|
|
}
|
|
if (offset == 0) {
|
|
// delay falls on the block boundary
|
|
if (queue[index]) {
|
|
transmit(queue[index], channel);
|
|
}
|
|
} else {
|
|
// delay requires grabbing data from 2 blocks
|
|
output = allocate();
|
|
if (!output) continue;
|
|
dst = output->data;
|
|
if (index > 0) {
|
|
prev = index - 1;
|
|
} else {
|
|
prev = DELAY_QUEUE_SIZE-1;
|
|
}
|
|
if (queue[prev]) {
|
|
end = queue[prev]->data + AUDIO_BLOCK_SAMPLES;
|
|
src = end - offset;
|
|
while (src < end) {
|
|
*dst++ = *src++; // TODO: optimize
|
|
}
|
|
} else {
|
|
end = dst + offset;
|
|
while (dst < end) {
|
|
*dst++ = 0;
|
|
}
|
|
}
|
|
end = output->data + AUDIO_BLOCK_SAMPLES;
|
|
if (queue[index]) {
|
|
src = queue[index]->data;
|
|
while (dst < end) {
|
|
*dst++ = *src++; // TODO: optimize
|
|
}
|
|
} else {
|
|
while (dst < end) {
|
|
*dst++ = 0;
|
|
}
|
|
}
|
|
transmit(output, channel);
|
|
release(output);
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
|