visus
/
teensy-audio
Watch 1
Star 0
Fork 0
Code Issues 0 Pull Requests 0 Releases 0 Wiki Activity
Browse Source

Add reverb effect, from Joao Rossi Filho

dds
PaulStoffregen 8 years ago
parent
877c40bda9
commit
4a6d5b57dd
4 changed files with 327 additions and 0 deletions
Unified View Show Diff Stats
  1. +1
    -0
      Audio.h
  2. +206
    -0
      effect_reverb.cpp
  3. +118
    -0
      effect_reverb.h
  4. +2
    -0
      keywords.txt

+ 1
- 0
Audio.h View File

#include "effect_delay.h" #include "effect_delay.h"
#include "effect_delay_ext.h" #include "effect_delay_ext.h"
#include "effect_midside.h" #include "effect_midside.h"
#include "effect_reverb.h"
#include "filter_biquad.h" #include "filter_biquad.h"
#include "filter_fir.h" #include "filter_fir.h"
#include "filter_variable.h" #include "filter_variable.h"

+ 206
- 0
effect_reverb.cpp View File

/*
* Copyright (c) 2016 Joao Rossi Filho
*
* 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 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.
*/

// https://github.com/joaoRossiFilho/teensy_reverb

#include "effect_reverb.h"
#include "utility/dspinst.h"
#include "math_helper.h"

void
AudioEffectReverb::_do_comb_apf(struct comb_apf *apf, int32_t *in_buf, int32_t *out_buf)
{
int32_t acc_x, acc_y, g;
int32_t w, z;
uint32_t n, buf_len;

g = apf->g;
buf_len = apf->buf_len;

for (n = 0; n < AUDIO_BLOCK_SAMPLES; n++) {
acc_y = apf->buffer[apf->rd_idx%buf_len];
acc_x = in_buf[n];

w = multiply_32x32_rshift32_rounded(g, acc_y);
acc_x += (w << 1);
z = multiply_32x32_rshift32_rounded(g, acc_x);
acc_y -= (z << 1);

apf->buffer[apf->wr_idx%buf_len] = acc_x;
out_buf[n] = acc_y;

apf->rd_idx++;
apf->wr_idx++;
}
}

void
AudioEffectReverb::_do_comb_lpf(struct comb_lpf *lpf, int32_t *in_buf, int32_t *out_buf)
{
int32_t x, y, w, z, g1, g2, z1;
uint32_t n, buf_len;

g1 = lpf->g1;
g2 = lpf->g2;
z1 = lpf->z1;
buf_len = lpf->buf_len;

for (n = 0; n < AUDIO_BLOCK_SAMPLES; n++) {
y = lpf->buffer[lpf->rd_idx%buf_len];
x = in_buf[n];

w = multiply_accumulate_32x32_rshift32_rounded(y, g2, z1);
z = multiply_accumulate_32x32_rshift32_rounded(x, g1, w);

z1 = w;
lpf->buffer[lpf->wr_idx%buf_len] = z;
out_buf[n] = y;

lpf->rd_idx++;
lpf->wr_idx++;
}

lpf->z1 = z1;
}

void
AudioEffectReverb::init_comb_filters(void)
{
int i;

g_flt_apf[0] = 0.7;
g_flt_apf[1] = -0.54;
g_flt_apf[2] = 0.6;

g2_flt_lpf = 0.985;

arm_float_to_q31(g_flt_apf, g_q31_apf, 3);
arm_float_to_q31(&g2_flt_lpf, &g2_q31_lpf, 1);

apf[0].buffer = apf1_buf;
apf[0].buf_len = APF1_BUF_LEN;
apf[0].delay = APF1_DLY_LEN;
apf[1].buffer = apf2_buf;
apf[1].buf_len = APF2_BUF_LEN;
apf[1].delay = APF2_DLY_LEN;
apf[2].buffer = apf3_buf;
apf[2].buf_len = APF3_BUF_LEN;
apf[2].delay = APF3_DLY_LEN;

for (i = 0; i < 3; i++) {
apf[i].g = g_q31_apf[i];
apf[i].wr_idx = 0;
apf[i].rd_idx = apf[i].wr_idx - apf[i].delay -1;
}

lpf[0].buffer = lpf1_buf;
lpf[0].buf_len = LPF1_BUF_LEN;
lpf[0].delay = LPF1_DLY_LEN;
lpf[1].buffer = lpf2_buf;
lpf[1].buf_len = LPF2_BUF_LEN;
lpf[1].delay = LPF2_DLY_LEN;
lpf[2].buffer = lpf3_buf;
lpf[2].buf_len = LPF3_BUF_LEN;
lpf[2].delay = LPF3_DLY_LEN;
lpf[3].buffer = lpf4_buf;
lpf[3].buf_len = LPF4_BUF_LEN;
lpf[3].delay = LPF4_DLY_LEN;

for (i = 0; i < 4; i++) {
lpf[i].g1 = g1_q31_lpf[i];
lpf[i].g2 = g2_q31_lpf;
lpf[i].wr_idx = 0;
lpf[i].rd_idx = lpf[i].wr_idx - lpf[i].delay -1;
}
}

void
AudioEffectReverb::clear_buffers(void)
{
memset(apf1_buf, 0, APF1_BUF_LEN);
memset(apf2_buf, 0, APF1_BUF_LEN);
memset(apf3_buf, 0, APF1_BUF_LEN);

memset(lpf1_buf, 0, LPF1_BUF_LEN);
memset(lpf2_buf, 0, LPF2_BUF_LEN);
memset(lpf3_buf, 0, LPF3_BUF_LEN);
memset(lpf4_buf, 0, LPF4_BUF_LEN);
}

void
AudioEffectReverb::reverbTime(float rt)
{
if (rt <= 0.0)
return;

reverb_time_sec = rt;

g1_flt_lpf[0] = powf(10.0, -(3.0*LPF1_DLY_SEC)/(reverb_time_sec));
g1_flt_lpf[1] = powf(10.0, -(3.0*LPF2_DLY_SEC)/(reverb_time_sec));
g1_flt_lpf[2] = powf(10.0, -(3.0*LPF3_DLY_SEC)/(reverb_time_sec));
g1_flt_lpf[3] = powf(10.0, -(3.0*LPF4_DLY_SEC)/(reverb_time_sec));

arm_float_to_q31(g1_flt_lpf, g1_q31_lpf, 4);

for (int i = 0; i < 4; i++)
lpf[i].g1 = g1_q31_lpf[i];
}

void
AudioEffectReverb::update(void)
{
audio_block_t *block;

if (!(block = receiveWritable()))
return;

if (!block->data)
return;

arm_q15_to_q31(block->data, q31_buf, AUDIO_BLOCK_SAMPLES);

_do_comb_apf(&apf[0], q31_buf, q31_buf);
_do_comb_apf(&apf[1], q31_buf, q31_buf);

_do_comb_lpf(&lpf[0], q31_buf, sum_buf);
arm_shift_q31(sum_buf, -3, sum_buf, AUDIO_BLOCK_SAMPLES);

_do_comb_lpf(&lpf[1], q31_buf, aux_buf);
arm_shift_q31(aux_buf, -3, aux_buf, AUDIO_BLOCK_SAMPLES);
arm_add_q31(sum_buf, aux_buf, sum_buf, AUDIO_BLOCK_SAMPLES);

_do_comb_lpf(&lpf[2], q31_buf, aux_buf);
arm_shift_q31(aux_buf, -3, aux_buf, AUDIO_BLOCK_SAMPLES);
arm_add_q31(sum_buf, aux_buf, sum_buf, AUDIO_BLOCK_SAMPLES);

_do_comb_lpf(&lpf[3], q31_buf, aux_buf);
arm_shift_q31(aux_buf, -3, aux_buf, AUDIO_BLOCK_SAMPLES);
arm_add_q31(sum_buf, aux_buf, sum_buf, AUDIO_BLOCK_SAMPLES);

_do_comb_apf(&apf[2], sum_buf, q31_buf);

arm_q31_to_q15(q31_buf, block->data, AUDIO_BLOCK_SAMPLES);

transmit(block, 0);
release(block);
}
/* EOF */

+ 118
- 0
effect_reverb.h View File

/* Reverb for Teensy
*
* Author: Joao Rossi Filho
* joaorossifilho@gmail.com
*
* Soon I'll make a commit with nice comments and discription
*
* Copyright (c) 2016 Joao Rossi FIlho
*
* 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 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.
*/

#ifndef effect_reverb_
#define effect_reverb_

#include "AudioStream.h"

#define APF1_BUF_LEN 600
#define APF2_BUF_LEN 1300
#define APF3_BUF_LEN 500

#define LPF1_BUF_LEN 1400
#define LPF2_BUF_LEN 1700
#define LPF3_BUF_LEN 1800
#define LPF4_BUF_LEN 2000

#define APF1_DLY_LEN 586
#define APF2_DLY_LEN 1239
#define APF3_DLY_LEN 485

#define LPF1_DLY_LEN 1398
#define LPF2_DLY_LEN 1637
#define LPF3_DLY_LEN 1774
#define LPF4_DLY_LEN 1947

#define LPF1_DLY_SEC 0.03171
#define LPF2_DLY_SEC 0.03711
#define LPF3_DLY_SEC 0.04023
#define LPF4_DLY_SEC 0.04414


class AudioEffectReverb : public AudioStream
{
public:
AudioEffectReverb(void) : AudioStream(1, inputQueueArray) {
init_comb_filters();
clear_buffers();
reverbTime(5.0);
}
virtual void update(void);
void reverbTime(float);

private:
struct comb_apf {
int32_t g;
int32_t *buffer;
uint32_t buf_len;
uint32_t delay, rd_idx, wr_idx;
};

struct comb_lpf {
int32_t g1, g2, z1;
int32_t *buffer;
uint32_t buf_len;
uint32_t delay, rd_idx, wr_idx;
};
void init_comb_filters(void);
void clear_buffers(void);
static void _do_comb_apf(struct comb_apf *apf, int32_t *in_buf, int32_t *out_buf);
static void _do_comb_lpf(struct comb_lpf *lpf, int32_t *in_buf, int32_t *out_buf);

audio_block_t *inputQueueArray[1];

struct comb_apf apf[3];
struct comb_lpf lpf[4];

float reverb_time_sec;

float g_flt_apf[3];
int32_t g_q31_apf[3];

float g1_flt_lpf[4];
int32_t g1_q31_lpf[4];

float g2_flt_lpf;
int32_t g2_q31_lpf;

int32_t apf1_buf[APF1_BUF_LEN];
int32_t apf2_buf[APF2_BUF_LEN];
int32_t apf3_buf[APF3_BUF_LEN];

int32_t lpf1_buf[LPF1_BUF_LEN];
int32_t lpf2_buf[LPF2_BUF_LEN];
int32_t lpf3_buf[LPF3_BUF_LEN];
int32_t lpf4_buf[LPF4_BUF_LEN];

int32_t q31_buf[AUDIO_BLOCK_SAMPLES];
int32_t sum_buf[AUDIO_BLOCK_SAMPLES];
int32_t aux_buf[AUDIO_BLOCK_SAMPLES];
};

#endif

+ 2
- 0
keywords.txt View File

AudioEffectDelay KEYWORD2 AudioEffectDelay KEYWORD2
AudioEffectDelayExternal KEYWORD2 AudioEffectDelayExternal KEYWORD2
AudioEffectBitcrusher KEYWORD2 AudioEffectBitcrusher KEYWORD2
AudioEffectReverb KEYWORD2
AudioEffectMidSide KEYWORD2 AudioEffectMidSide KEYWORD2
AudioFilterBiquad KEYWORD2 AudioFilterBiquad KEYWORD2
AudioFilterFIR KEYWORD2 AudioFilterFIR KEYWORD2
unmuteInput KEYWORD2 unmuteInput KEYWORD2
enableDither KEYWORD2 enableDither KEYWORD2
disableDither KEYWORD2 disableDither KEYWORD2
reverbTime KEYWORD2
frequency KEYWORD2 frequency KEYWORD2
phase KEYWORD2 phase KEYWORD2
amplitude KEYWORD2 amplitude KEYWORD2

Write Preview
Loading…
Cancel
Save