pinebuds/thirdparty/noise_tracker_lib/noise_tracker.c

#include "noise_tracker.h"
#include "audio_dump.h"
#include "hal_trace.h"
#include <math.h>

//#define NT_DUMP_AUDIO_DATA

#define SQUARE(x) ((x) * (x))
#define LIN2DB(x) (10.f * log10f(x))

#define NORMAL_SCALE (1.f / 32768 / 32768)

static NoiseTrackerCallback _callback;
static int _threshold;
static int _ch_num;

static float vec_power(int16_t *buf, uint32_t len, int stride) {
  float sum = 0.f;
  for (uint32_t i = 0; i < len; i += stride)
    sum += SQUARE(buf[i]);

  return sum;
}

void noise_tracker_init(NoiseTrackerCallback cb, int ch_num, int threshold) {
  _callback = cb;
  _threshold = threshold;
  _ch_num = ch_num;

#ifdef NT_DUMP_AUDIO_DATA
  audio_dump_init(240 * ANC_NOISE_TRACKER_CHANNEL_NUM, sizeof(int16_t), 1);
#endif
}

void noise_tracker_process(int16_t *buf, uint32_t len) {
  float scale = 1.f / len * NORMAL_SCALE;
  float maxPowerdB = -90;

#ifdef NT_DUMP_AUDIO_DATA
  audio_dump_clear_up();
  audio_dump_add_channel_data(0, buf, len);
  audio_dump_run();
#endif

  for (int i = 0; i < _ch_num; i++) {
    float power = vec_power(&buf[i], len, _ch_num) * scale;
    float powerdB = LIN2DB(power);
    maxPowerdB = MAX(maxPowerdB, powerdB);

    // TRACE(3,"[%s] powerdB ch[%d] = %d", __FUNCTION__, i, (int)powerdB);
  }

  if (maxPowerdB > _threshold) {
    _callback(maxPowerdB);
  }
}