+static void set_meta(AVDictionary **metadata, int chan, const char *key,
+ const char *fmt, double val)
+{
+ uint8_t value[128];
+ uint8_t key2[128];
+
+ snprintf(value, sizeof(value), fmt, val);
+ if (chan)
+ snprintf(key2, sizeof(key2), "lavfi.astats.%d.%s", chan, key);
+ else
+ snprintf(key2, sizeof(key2), "lavfi.astats.%s", key);
+ av_dict_set(metadata, key2, value, 0);
+}
+
+#define LINEAR_TO_DB(x) (log10(x) * 20)
+
+static void set_metadata(AudioStatsContext *s, AVDictionary **metadata)
+{
+ uint64_t mask = 0, min_count = 0, max_count = 0, nb_samples = 0;
+ double min_runs = 0, max_runs = 0,
+ min = DBL_MAX, max = DBL_MIN, min_diff = DBL_MAX, max_diff = 0,
+ max_sigma_x = 0,
+ diff1_sum = 0,
+ sigma_x = 0,
+ sigma_x2 = 0,
+ min_sigma_x2 = DBL_MAX,
+ max_sigma_x2 = DBL_MIN;
+ int c;
+
+ for (c = 0; c < s->nb_channels; c++) {
+ ChannelStats *p = &s->chstats[c];
+
+ if (p->nb_samples < s->tc_samples)
+ p->min_sigma_x2 = p->max_sigma_x2 = p->sigma_x2 / p->nb_samples;
+
+ min = FFMIN(min, p->min);
+ max = FFMAX(max, p->max);
+ min_diff = FFMIN(min_diff, p->min_diff);
+ max_diff = FFMAX(max_diff, p->max_diff);
+ diff1_sum += p->diff1_sum,
+ min_sigma_x2 = FFMIN(min_sigma_x2, p->min_sigma_x2);
+ max_sigma_x2 = FFMAX(max_sigma_x2, p->max_sigma_x2);
+ sigma_x += p->sigma_x;
+ sigma_x2 += p->sigma_x2;
+ min_count += p->min_count;
+ max_count += p->max_count;
+ min_runs += p->min_runs;
+ max_runs += p->max_runs;
+ mask |= p->mask;
+ nb_samples += p->nb_samples;
+ if (fabs(p->sigma_x) > fabs(max_sigma_x))
+ max_sigma_x = p->sigma_x;
+
+ set_meta(metadata, c + 1, "DC_offset", "%f", p->sigma_x / p->nb_samples);
+ set_meta(metadata, c + 1, "Min_level", "%f", p->min);
+ set_meta(metadata, c + 1, "Max_level", "%f", p->max);
+ set_meta(metadata, c + 1, "Min_difference", "%f", p->min_diff);
+ set_meta(metadata, c + 1, "Max_difference", "%f", p->max_diff);
+ set_meta(metadata, c + 1, "Mean_difference", "%f", p->diff1_sum / (p->nb_samples - 1));
+ set_meta(metadata, c + 1, "Peak_level", "%f", LINEAR_TO_DB(FFMAX(-p->min, p->max)));
+ set_meta(metadata, c + 1, "RMS_level", "%f", LINEAR_TO_DB(sqrt(p->sigma_x2 / p->nb_samples)));
+ set_meta(metadata, c + 1, "RMS_peak", "%f", LINEAR_TO_DB(sqrt(p->max_sigma_x2)));
+ set_meta(metadata, c + 1, "RMS_trough", "%f", LINEAR_TO_DB(sqrt(p->min_sigma_x2)));
+ set_meta(metadata, c + 1, "Crest_factor", "%f", p->sigma_x2 ? FFMAX(-p->min, p->max) / sqrt(p->sigma_x2 / p->nb_samples) : 1);
+ set_meta(metadata, c + 1, "Flat_factor", "%f", LINEAR_TO_DB((p->min_runs + p->max_runs) / (p->min_count + p->max_count)));
+ set_meta(metadata, c + 1, "Peak_count", "%f", (float)(p->min_count + p->max_count));
+ set_meta(metadata, c + 1, "Bit_depth", "%f", bit_depth(p->mask));
+ }
+
+ set_meta(metadata, 0, "Overall.DC_offset", "%f", max_sigma_x / (nb_samples / s->nb_channels));
+ set_meta(metadata, 0, "Overall.Min_level", "%f", min);
+ set_meta(metadata, 0, "Overall.Max_level", "%f", max);
+ set_meta(metadata, 0, "Overall.Min_difference", "%f", min_diff);
+ set_meta(metadata, 0, "Overall.Max_difference", "%f", max_diff);
+ set_meta(metadata, 0, "Overall.Mean_difference", "%f", diff1_sum / (nb_samples - s->nb_channels));
+ set_meta(metadata, 0, "Overall.Peak_level", "%f", LINEAR_TO_DB(FFMAX(-min, max)));
+ set_meta(metadata, 0, "Overall.RMS_level", "%f", LINEAR_TO_DB(sqrt(sigma_x2 / nb_samples)));
+ set_meta(metadata, 0, "Overall.RMS_peak", "%f", LINEAR_TO_DB(sqrt(max_sigma_x2)));
+ set_meta(metadata, 0, "Overall.RMS_trough", "%f", LINEAR_TO_DB(sqrt(min_sigma_x2)));
+ set_meta(metadata, 0, "Overall.Flat_factor", "%f", LINEAR_TO_DB((min_runs + max_runs) / (min_count + max_count)));
+ set_meta(metadata, 0, "Overall.Peak_count", "%f", (float)(min_count + max_count) / (double)s->nb_channels);
+ set_meta(metadata, 0, "Overall.Bit_depth", "%f", bit_depth(mask));
+ set_meta(metadata, 0, "Overall.Number_of_samples", "%f", nb_samples / s->nb_channels);
+}
+