You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
MicroDexed/effect_delay_ext8.h

80 lines
2.9 KiB

/*
MicroDexed
MicroDexed is a port of the Dexed sound engine
Dexed ist heavily based on https://github.com/google/music-synthesizer-for-android
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
effect_delay_ext8 is a special delay class for APS6404L-3SQR based memory chips on
a Teensy-4.1. The cod is a combination of the PJRC delay_ext class and suggestions
from https://forum.pjrc.com/threads/29276-Limits-of-delay-effect-in-audio-library/page5?highlight=APS6404L-3SQR
*/
#ifndef effect_delay_ext8_h_
#define effect_delay_ext8_h_
#include "Arduino.h"
#include "AudioStream.h"
#include "spi_interrupt.h"
class AudioEffectDelayExternal8 : public AudioStream
{
public:
AudioEffectDelayExternal8() : AudioStream(1, inputQueueArray) {
initialize(4194304);
}
AudioEffectDelayExternal8(float milliseconds=1e6)
: AudioStream(1, inputQueueArray) {
uint32_t n = (milliseconds*(AUDIO_SAMPLE_RATE_EXACT/1000.0f))+0.5f;
initialize(n);
}
void delay(uint8_t channel, float milliseconds) {
if (channel >= 8) return;
if (milliseconds < 0.0f) milliseconds = 0.0f;
uint32_t n = (milliseconds*(AUDIO_SAMPLE_RATE_EXACT/1000.0f))+0.5f;
n += AUDIO_BLOCK_SAMPLES;
if (n > memory_length - AUDIO_BLOCK_SAMPLES)
n = memory_length - AUDIO_BLOCK_SAMPLES;
delay_length[channel] = n;
uint8_t mask = activemask;
if (activemask == 0) AudioStartUsingSPI();
activemask = mask | (1<<channel);
}
void disable(uint8_t channel) {
if (channel >= 8) return;
uint8_t mask = activemask & ~(1<<channel);
activemask = mask;
if (mask == 0) AudioStopUsingSPI();
}
virtual void update(void);
private:
void initialize(uint32_t samples);
void read(uint32_t address, uint32_t count, int16_t *data);
void write(uint32_t address, uint32_t count, const int16_t *data);
void zero(uint32_t address, uint32_t count) {
write(address, count, NULL);
}
uint32_t memory_begin; // the first address in the memory we're using
uint32_t memory_length; // the amount of memory we're using
uint32_t head_offset; // head index (incoming) data into external memory
uint32_t delay_length[8]; // # of sample delay for each channel (128 = no delay)
uint8_t activemask; // which output channels are active
static uint32_t allocated;
audio_block_t *inputQueueArray[1];
};
#endif