/*
* Squeezelite for esp32
*
* (c) Philippe G. 2020, philippe_44@outlook.com
*
* This software is released under the MIT License.
* https://opensource.org/licenses/MIT
*
*/
#include "math.h"
#include "platform_config.h"
#include "squeezelite.h"
#include "equalizer.h"
#include "esp_equalizer.h"
#define EQ_BANDS 10
static log_level loglevel = lINFO;
static EXT_RAM_ATTR struct {
void *handle;
float loudness, volume;
uint32_t samplerate;
float gain[EQ_BANDS], loudness_gain[EQ_BANDS];
bool update;
} equalizer;
#define POLYNOME_COUNT 6
static const float loudness_envelope_coefficients[EQ_BANDS][POLYNOME_COUNT] = {
{5.5169301499257067e+001, 6.3671410796029004e-001,
-4.2663226432095233e-002, 8.1063072336581246e-004,
-7.3621858933917722e-006, 2.5349489594339575e-008},
{3.7716143859944118e+001, 1.2355293276538579e+000,
-6.6435374582217863e-002, 1.2976763440259382e-003,
-1.1978732496353172e-005, 4.1664114634622593e-008},
{2.5103632377146837e+001, 1.3259150615414637e+000,
-6.6332442135695099e-002, 1.2845279812261677e-003,
-1.1799885217545631e-005, 4.0925911584040685e-008},
{1.3159168212144563e+001, 8.8149357628440639e-001,
-4.0384121097225931e-002, 7.3843501027501322e-004,
-6.5508794453097008e-006, 2.2221997141120518e-008},
{5.1337853800151700e+000, 4.0817077967582394e-001,
-1.4107826528626457e-002, 1.5251066311713760e-004,
-3.6689819583740298e-007, -2.0390798774727989e-009},
{3.1432364156464315e-001, 9.1260548140023004e-002,
-3.5012124633183438e-004, -8.6023911664606992e-005,
1.6785606828245921e-006, -8.8269731094371646e-009},
{-4.0965062397075833e+000, 1.3667010948271402e-001,
2.4775896786988390e-004, -9.6620399661858641e-005,
1.7733690952379155e-006, -9.1583104942496635e-009},
{-9.0275786029994176e+000, 2.6226938845184250e-001,
-6.5777547972402156e-003, 1.0045957188977551e-004,
-7.8851000325128971e-007, 2.4639885209682384e-009},
{-4.4275018199195815e+000, 4.5399572638241725e-001,
-2.4034902766833462e-002, 5.9828953622534668e-004,
-6.2893971217140864e-006, 2.3133296592719627e-008},
{1.4243299202697818e+001, 3.6984458807056630e-001,
-3.0413994109395680e-002, 7.6700105080386904e-004,
-8.2777185209388079e-006, 3.1352890650784970e-008} };
/****************************************************************************************
* calculate loudness gains
*/
static void calculate_loudness(void) {
char trace[EQ_BANDS * 5 + 1];
size_t n = 0;
for (int i = 0; i < EQ_BANDS; i++) {
for (int j = 0; j < POLYNOME_COUNT && equalizer.loudness != 0; j++) {
equalizer.loudness_gain[i] +=
loudness_envelope_coefficients[i][j] * pow(equalizer.volume, j);
}
equalizer.loudness_gain[i] *= equalizer.loudness / 2;
n += sprintf(trace + n, "%.2g%c", equalizer.loudness_gain[i], i < EQ_BANDS ? ',' : '\0');
}
LOG_INFO("loudness %s", trace);
}
/****************************************************************************************
* initialize equalizer
*/
void equalizer_init(void) {
// handle equalizer
char *config = config_alloc_get(NVS_TYPE_STR, "equalizer");
char *p = strtok(config, ", !");
for (int i = 0; p && i < EQ_BANDS; i++) {
equalizer.gain[i] = atoi(p);
p = strtok(NULL, ", :");
}
free(config);
// handle loudness
config = config_alloc_get(NVS_TYPE_STR, "loudness");
equalizer.loudness = atof(config) / 10.0;
free(config);
}
/****************************************************************************************
* close equalizer
*/
void equalizer_close(void) {
if (equalizer.handle) {
esp_equalizer_uninit(equalizer.handle);
equalizer.handle = NULL;
}
}
/****************************************************************************************
* change sample rate
*/
void equalizer_set_samplerate(uint32_t samplerate) {
#if BYTES_PER_FRAME == 4
if (equalizer.samplerate != samplerate) equalizer_close();
equalizer.samplerate = samplerate;
equalizer.update = true;
LOG_INFO("equalizer sample rate %u", samplerate);
#else
LOG_INFO("no equalizer with 32 bits samples");
#endif
}
/****************************************************************************************
* get volume update and recalculate loudness according to
*/
void equalizer_set_volume(unsigned left, unsigned right) {
#if BYTES_PER_FRAME == 4
float volume = (left + right) / 2;
// do classic dB conversion and scale it 0..100
if (volume) volume = log2(volume);
volume = volume / 16.0 * 100.0;
// LMS has the bad habit to send multiple volume commands
if (volume != equalizer.volume && equalizer.loudness) {
equalizer.volume = volume;
calculate_loudness();
equalizer.update = true;
}
#endif
}
/****************************************************************************************
* change gains from LMS
*/
void equalizer_set_gain(int8_t *gain) {
#if BYTES_PER_FRAME == 4
char config[EQ_BANDS * 4 + 1] = { };
int n = 0;
for (int i = 0; i < EQ_BANDS; i++) {
equalizer.gain[i] = gain[i];
n += sprintf(config + n, "%d,", gain[i]);
}
config[n-1] = '\0';
config_set_value(NVS_TYPE_STR, "equalizer", config);
// update only if something changed
if (!memcmp(equalizer.gain, gain, EQ_BANDS)) equalizer.update = true;
LOG_INFO("equalizer gain %s", config);
#else
LOG_INFO("no equalizer with 32 bits samples");
#endif
}
/****************************************************************************************
* change loudness from LMS
*/
void equalizer_set_loudness(uint8_t loudness) {
#if BYTES_PER_FRAME == 4
char p[4];
itoa(loudness, p, 10);
config_set_value(NVS_TYPE_STR, "loudness", p);
// update loudness gains as a factor of loudness and volume
if (equalizer.loudness != loudness / 10.0) {
equalizer.loudness = loudness / 10.0;
calculate_loudness();
equalizer.update = true;
}
LOG_INFO("loudness %u", (unsigned) loudness);
#else
LOG_INFO("no equalizer with 32 bits samples");
#endif
}
/****************************************************************************************
* process equalizer
*/
void equalizer_process(uint8_t *buf, uint32_t bytes) {
#if BYTES_PER_FRAME == 4
// don't want to process with output locked, so take the small risk to miss one parametric update
if (equalizer.update) {
equalizer.update = false;
if (equalizer.samplerate != 11025 && equalizer.samplerate != 22050 && equalizer.samplerate != 44100 && equalizer.samplerate != 48000) {
LOG_WARN("equalizer only supports 11025, 22050, 44100 and 48000 sample rates, not %u", equalizer.samplerate);
return;
}
if (!equalizer.handle && ((equalizer.handle = esp_equalizer_init(2, equalizer.samplerate, EQ_BANDS, 0)) == NULL)) {
LOG_WARN("can't init equalizer");
return;
}
bool active = false;
for (int i = 0; i < EQ_BANDS; i++) {
float gain = equalizer.gain[i] + equalizer.loudness_gain[i];
esp_equalizer_set_band_value(equalizer.handle, gain, i, 0);
esp_equalizer_set_band_value(equalizer.handle, gain, i, 1);
active |= gain != 0;
}
// at the end do not activate equalizer if all gain are 0
if (!active) equalizer_close();
LOG_INFO("equalizer %s", active ? "actived" : "deactivated");
}
if (equalizer.handle) {
esp_equalizer_process(equalizer.handle, buf, bytes, equalizer.samplerate, 2);
}
#endif
}