libavfilter/af_aspectralstats.c

   1 /*
   2  * Copyright (c) 2021 Paul B Mahol
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <float.h>
  22 #include <math.h>
  23
  24 #include "libavutil/mem.h"
  25 #include "libavutil/opt.h"
  26 #include "libavutil/tx.h"
  27 #include "audio.h"
  28 #include "avfilter.h"
  29 #include "filters.h"
  30 #include "window_func.h"
  31
  32 #define MEASURE_ALL       UINT_MAX
  33 #define MEASURE_NONE      0
  34 #define MEASURE_MEAN     (1 <<  0)
  35 #define MEASURE_VARIANCE (1 <<  1)
  36 #define MEASURE_CENTROID (1 <<  2)
  37 #define MEASURE_SPREAD   (1 <<  3)
  38 #define MEASURE_SKEWNESS (1 <<  4)
  39 #define MEASURE_KURTOSIS (1 <<  5)
  40 #define MEASURE_ENTROPY  (1 <<  6)
  41 #define MEASURE_FLATNESS (1 <<  7)
  42 #define MEASURE_CREST    (1 <<  8)
  43 #define MEASURE_FLUX     (1 <<  9)
  44 #define MEASURE_SLOPE    (1 << 10)
  45 #define MEASURE_DECREASE (1 << 11)
  46 #define MEASURE_ROLLOFF  (1 << 12)
  47
  48 typedef struct ChannelSpectralStats {
  49     float mean;
  50     float variance;
  51     float centroid;
  52     float spread;
  53     float skewness;
  54     float kurtosis;
  55     float entropy;
  56     float flatness;
  57     float crest;
  58     float flux;
  59     float slope;
  60     float decrease;
  61     float rolloff;
  62 } ChannelSpectralStats;
  63
  64 typedef struct AudioSpectralStatsContext {
  65     const AVClass *class;
  66     unsigned measure;
  67     int win_size;
  68     int win_func;
  69     float overlap;
  70     int nb_channels;
  71     int hop_size;
  72     ChannelSpectralStats *stats;
  73     float *window_func_lut;
  74     av_tx_fn tx_fn;
  75     AVTXContext **fft;
  76     AVComplexFloat **fft_in;
  77     AVComplexFloat **fft_out;
  78     float **prev_magnitude;
  79     float **magnitude;
  80     AVFrame *window;
  81 } AudioSpectralStatsContext;
  82
  83 #define OFFSET(x) offsetof(AudioSpectralStatsContext, x)
  84 #define A AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
  85
  86 static const AVOption aspectralstats_options[] = {
  87     { "win_size", "set the window size", OFFSET(win_size), AV_OPT_TYPE_INT, {.i64=2048}, 32, 65536, A },
  88     WIN_FUNC_OPTION("win_func", OFFSET(win_func), A, WFUNC_HANNING),
  89     { "overlap", "set window overlap", OFFSET(overlap), AV_OPT_TYPE_FLOAT, {.dbl=0.5}, 0,  1, A },
  90     { "measure", "select the parameters which are measured", OFFSET(measure), AV_OPT_TYPE_FLAGS, {.i64=MEASURE_ALL}, 0, UINT_MAX, A, .unit = "measure" },
  91     { "none",     "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_NONE    }, 0, 0, A, .unit = "measure" },
  92     { "all",      "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_ALL     }, 0, 0, A, .unit = "measure" },
  93     { "mean",     "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_MEAN    }, 0, 0, A, .unit = "measure" },
  94     { "variance", "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_VARIANCE}, 0, 0, A, .unit = "measure" },
  95     { "centroid", "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_CENTROID}, 0, 0, A, .unit = "measure" },
  96     { "spread",   "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_SPREAD  }, 0, 0, A, .unit = "measure" },
  97     { "skewness", "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_SKEWNESS}, 0, 0, A, .unit = "measure" },
  98     { "kurtosis", "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_KURTOSIS}, 0, 0, A, .unit = "measure" },
  99     { "entropy",  "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_ENTROPY }, 0, 0, A, .unit = "measure" },
 100     { "flatness", "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_FLATNESS}, 0, 0, A, .unit = "measure" },
 101     { "crest",    "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_CREST   }, 0, 0, A, .unit = "measure" },
 102     { "flux",     "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_FLUX    }, 0, 0, A, .unit = "measure" },
 103     { "slope",    "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_SLOPE   }, 0, 0, A, .unit = "measure" },
 104     { "decrease", "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_DECREASE}, 0, 0, A, .unit = "measure" },
 105     { "rolloff",  "", 0, AV_OPT_TYPE_CONST, {.i64=MEASURE_ROLLOFF }, 0, 0, A, .unit = "measure" },
 106     { NULL }
 107 };
 108
 109 AVFILTER_DEFINE_CLASS(aspectralstats);
 110
 111 static int config_output(AVFilterLink *outlink)
 112 {
 113     AudioSpectralStatsContext *s = outlink->src->priv;
 114     float overlap, scale = 1.f;
 115     int ret;
 116
 117     s->nb_channels = outlink->ch_layout.nb_channels;
 118     s->window_func_lut = av_realloc_f(s->window_func_lut, s->win_size,
 119                                       sizeof(*s->window_func_lut));
 120     if (!s->window_func_lut)
 121         return AVERROR(ENOMEM);
 122     generate_window_func(s->window_func_lut, s->win_size, s->win_func, &overlap);
 123     if (s->overlap == 1.f)
 124         s->overlap = overlap;
 125
 126     s->hop_size = s->win_size * (1.f - s->overlap);
 127     if (s->hop_size <= 0)
 128         return AVERROR(EINVAL);
 129
 130     s->stats = av_calloc(s->nb_channels, sizeof(*s->stats));
 131     if (!s->stats)
 132         return AVERROR(ENOMEM);
 133
 134     s->fft = av_calloc(s->nb_channels, sizeof(*s->fft));
 135     if (!s->fft)
 136         return AVERROR(ENOMEM);
 137
 138     s->magnitude = av_calloc(s->nb_channels, sizeof(*s->magnitude));
 139     if (!s->magnitude)
 140         return AVERROR(ENOMEM);
 141
 142     s->prev_magnitude = av_calloc(s->nb_channels, sizeof(*s->prev_magnitude));
 143     if (!s->prev_magnitude)
 144         return AVERROR(ENOMEM);
 145
 146     s->fft_in = av_calloc(s->nb_channels, sizeof(*s->fft_in));
 147     if (!s->fft_in)
 148         return AVERROR(ENOMEM);
 149
 150     s->fft_out = av_calloc(s->nb_channels, sizeof(*s->fft_out));
 151     if (!s->fft_out)
 152         return AVERROR(ENOMEM);
 153
 154     for (int ch = 0; ch < s->nb_channels; ch++) {
 155         ret = av_tx_init(&s->fft[ch], &s->tx_fn, AV_TX_FLOAT_FFT, 0, s->win_size, &scale, 0);
 156         if (ret < 0)
 157             return ret;
 158
 159         s->fft_in[ch] = av_calloc(s->win_size, sizeof(**s->fft_in));
 160         if (!s->fft_in[ch])
 161             return AVERROR(ENOMEM);
 162
 163         s->fft_out[ch] = av_calloc(s->win_size, sizeof(**s->fft_out));
 164         if (!s->fft_out[ch])
 165             return AVERROR(ENOMEM);
 166
 167         s->magnitude[ch] = av_calloc(s->win_size, sizeof(**s->magnitude));
 168         if (!s->magnitude[ch])
 169             return AVERROR(ENOMEM);
 170
 171         s->prev_magnitude[ch] = av_calloc(s->win_size, sizeof(**s->prev_magnitude));
 172         if (!s->prev_magnitude[ch])
 173             return AVERROR(ENOMEM);
 174     }
 175
 176     s->window = ff_get_audio_buffer(outlink, s->win_size);
 177     if (!s->window)
 178         return AVERROR(ENOMEM);
 179
 180     return 0;
 181 }
 182
 183 static void set_meta(AVDictionary **metadata, int chan, const char *key,
 184                      const char *fmt, float val)
 185 {
 186     uint8_t value[128];
 187     uint8_t key2[128];
 188
 189     snprintf(value, sizeof(value), fmt, val);
 190     if (chan)
 191         snprintf(key2, sizeof(key2), "lavfi.aspectralstats.%d.%s", chan, key);
 192     else
 193         snprintf(key2, sizeof(key2), "lavfi.aspectralstats.%s", key);
 194     av_dict_set(metadata, key2, value, 0);
 195 }
 196
 197 static void set_metadata(AudioSpectralStatsContext *s, AVDictionary **metadata)
 198 {
 199     for (int ch = 0; ch < s->nb_channels; ch++) {
 200         ChannelSpectralStats *stats = &s->stats[ch];
 201
 202         if (s->measure & MEASURE_MEAN)
 203             set_meta(metadata, ch + 1, "mean",     "%g", stats->mean);
 204         if (s->measure & MEASURE_VARIANCE)
 205             set_meta(metadata, ch + 1, "variance", "%g", stats->variance);
 206         if (s->measure & MEASURE_CENTROID)
 207             set_meta(metadata, ch + 1, "centroid", "%g", stats->centroid);
 208         if (s->measure & MEASURE_SPREAD)
 209             set_meta(metadata, ch + 1, "spread",   "%g", stats->spread);
 210         if (s->measure & MEASURE_SKEWNESS)
 211             set_meta(metadata, ch + 1, "skewness", "%g", stats->skewness);
 212         if (s->measure & MEASURE_KURTOSIS)
 213             set_meta(metadata, ch + 1, "kurtosis", "%g", stats->kurtosis);
 214         if (s->measure & MEASURE_ENTROPY)
 215             set_meta(metadata, ch + 1, "entropy",  "%g", stats->entropy);
 216         if (s->measure & MEASURE_FLATNESS)
 217             set_meta(metadata, ch + 1, "flatness", "%g", stats->flatness);
 218         if (s->measure & MEASURE_CREST)
 219             set_meta(metadata, ch + 1, "crest",    "%g", stats->crest);
 220         if (s->measure & MEASURE_FLUX)
 221             set_meta(metadata, ch + 1, "flux",     "%g", stats->flux);
 222         if (s->measure & MEASURE_SLOPE)
 223             set_meta(metadata, ch + 1, "slope",    "%g", stats->slope);
 224         if (s->measure & MEASURE_DECREASE)
 225             set_meta(metadata, ch + 1, "decrease", "%g", stats->decrease);
 226         if (s->measure & MEASURE_ROLLOFF)
 227             set_meta(metadata, ch + 1, "rolloff",  "%g", stats->rolloff);
 228     }
 229 }
 230
 231 static float spectral_mean(const float *const spectral, int size, int max_freq)
 232 {
 233     float sum = 0.f;
 234
 235     for (int n = 0; n < size; n++)
 236         sum += spectral[n];
 237
 238     return sum / size;
 239 }
 240
 241 static float sqrf(float a)
 242 {
 243     return a * a;
 244 }
 245
 246 static float spectral_variance(const float *const spectral, int size, int max_freq, float mean)
 247 {
 248     float sum = 0.f;
 249
 250     for (int n = 0; n < size; n++)
 251         sum += sqrf(spectral[n] - mean);
 252
 253     return sum / size;
 254 }
 255
 256 static float spectral_centroid(const float *const spectral, int size, int max_freq)
 257 {
 258     const float scale = max_freq / (float)size;
 259     float num = 0.f, den = 0.f;
 260
 261     for (int n = 0; n < size; n++) {
 262         num += spectral[n] * n * scale;
 263         den += spectral[n];
 264     }
 265
 266     if (den <= FLT_EPSILON)
 267         return 1.f;
 268     return num / den;
 269 }
 270
 271 static float spectral_spread(const float *const spectral, int size, int max_freq, float centroid)
 272 {
 273     const float scale = max_freq / (float)size;
 274     float num = 0.f, den = 0.f;
 275
 276     for (int n = 0; n < size; n++) {
 277         num += spectral[n] * sqrf(n * scale - centroid);
 278         den += spectral[n];
 279     }
 280
 281     if (den <= FLT_EPSILON)
 282         return 1.f;
 283     return sqrtf(num / den);
 284 }
 285
 286 static float cbrf(float a)
 287 {
 288     return a * a * a;
 289 }
 290
 291 static float spectral_skewness(const float *const spectral, int size, int max_freq, float centroid, float spread)
 292 {
 293     const float scale = max_freq / (float)size;
 294     float num = 0.f, den = 0.f;
 295
 296     for (int n = 0; n < size; n++) {
 297         num += spectral[n] * cbrf(n * scale - centroid);
 298         den += spectral[n];
 299     }
 300
 301     den *= cbrf(spread);
 302     if (den <= FLT_EPSILON)
 303         return 1.f;
 304     return num / den;
 305 }
 306
 307 static float spectral_kurtosis(const float *const spectral, int size, int max_freq, float centroid, float spread)
 308 {
 309     const float scale = max_freq / (float)size;
 310     float num = 0.f, den = 0.f;
 311
 312     for (int n = 0; n < size; n++) {
 313         num += spectral[n] * sqrf(sqrf(n * scale - centroid));
 314         den += spectral[n];
 315     }
 316
 317     den *= sqrf(sqrf(spread));
 318     if (den <= FLT_EPSILON)
 319         return 1.f;
 320     return num / den;
 321 }
 322
 323 static float spectral_entropy(const float *const spectral, int size, int max_freq)
 324 {
 325     float num = 0.f, den = 0.f;
 326
 327     for (int n = 0; n < size; n++) {
 328         num += spectral[n] * logf(spectral[n] + FLT_EPSILON);
 329     }
 330
 331     den = logf(size);
 332     if (den <= FLT_EPSILON)
 333         return 1.f;
 334     return -num / den;
 335 }
 336
 337 static float spectral_flatness(const float *const spectral, int size, int max_freq)
 338 {
 339     float num = 0.f, den = 0.f;
 340
 341     for (int n = 0; n < size; n++) {
 342         float v = FLT_EPSILON + spectral[n];
 343         num += logf(v);
 344         den += v;
 345     }
 346
 347     num /= size;
 348     den /= size;
 349     num = expf(num);
 350     if (den <= FLT_EPSILON)
 351         return 0.f;
 352     return num / den;
 353 }
 354
 355 static float spectral_crest(const float *const spectral, int size, int max_freq)
 356 {
 357     float max = 0.f, mean = 0.f;
 358
 359     for (int n = 0; n < size; n++) {
 360         max = fmaxf(max, spectral[n]);
 361         mean += spectral[n];
 362     }
 363
 364     mean /= size;
 365     if (mean <= FLT_EPSILON)
 366         return 0.f;
 367     return max / mean;
 368 }
 369
 370 static float spectral_flux(const float *const spectral, const float *const prev_spectral,
 371                            int size, int max_freq)
 372 {
 373     float sum = 0.f;
 374
 375     for (int n = 0; n < size; n++)
 376         sum += sqrf(spectral[n] - prev_spectral[n]);
 377
 378     return sqrtf(sum);
 379 }
 380
 381 static float spectral_slope(const float *const spectral, int size, int max_freq)
 382 {
 383     const float mean_freq = size * 0.5f;
 384     float mean_spectral = 0.f, num = 0.f, den = 0.f;
 385
 386     for (int n = 0; n < size; n++)
 387         mean_spectral += spectral[n];
 388     mean_spectral /= size;
 389
 390     for (int n = 0; n < size; n++) {
 391         num += ((n - mean_freq) / mean_freq) * (spectral[n] - mean_spectral);
 392         den += sqrf((n - mean_freq) / mean_freq);
 393     }
 394
 395     if (fabsf(den) <= FLT_EPSILON)
 396         return 0.f;
 397     return num / den;
 398 }
 399
 400 static float spectral_decrease(const float *const spectral, int size, int max_freq)
 401 {
 402     float num = 0.f, den = 0.f;
 403
 404     for (int n = 1; n < size; n++) {
 405         num += (spectral[n] - spectral[0]) / n;
 406         den += spectral[n];
 407     }
 408
 409     if (den <= FLT_EPSILON)
 410         return 0.f;
 411     return num / den;
 412 }
 413
 414 static float spectral_rolloff(const float *const spectral, int size, int max_freq)
 415 {
 416     const float scale = max_freq / (float)size;
 417     float norm = 0.f, sum = 0.f;
 418     int idx = 0.f;
 419
 420     for (int n = 0; n < size; n++)
 421         norm += spectral[n];
 422     norm *= 0.85f;
 423
 424     for (int n = 0; n < size; n++) {
 425         sum += spectral[n];
 426         if (sum >= norm) {
 427             idx = n;
 428             break;
 429         }
 430     }
 431
 432     return idx * scale;
 433 }
 434
 435 static int filter_channel(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 436 {
 437     AudioSpectralStatsContext *s = ctx->priv;
 438     const float *window_func_lut = s->window_func_lut;
 439     AVFrame *in = arg;
 440     const int channels = s->nb_channels;
 441     const int start = (channels * jobnr) / nb_jobs;
 442     const int end = (channels * (jobnr+1)) / nb_jobs;
 443     const int offset = s->win_size - s->hop_size;
 444
 445     for (int ch = start; ch < end; ch++) {
 446         float *window = (float *)s->window->extended_data[ch];
 447         ChannelSpectralStats *stats = &s->stats[ch];
 448         AVComplexFloat *fft_out = s->fft_out[ch];
 449         AVComplexFloat *fft_in = s->fft_in[ch];
 450         float *magnitude = s->magnitude[ch];
 451         float *prev_magnitude = s->prev_magnitude[ch];
 452         const float scale = 1.f / s->win_size;
 453
 454         memmove(window, &window[s->hop_size], offset * sizeof(float));
 455         memcpy(&window[offset], in->extended_data[ch], in->nb_samples * sizeof(float));
 456         memset(&window[offset + in->nb_samples], 0, (s->hop_size - in->nb_samples) * sizeof(float));
 457
 458         for (int n = 0; n < s->win_size; n++) {
 459             fft_in[n].re = window[n] * window_func_lut[n];
 460             fft_in[n].im = 0;
 461         }
 462
 463         s->tx_fn(s->fft[ch], fft_out, fft_in, sizeof(*fft_in));
 464
 465         for (int n = 0; n < s->win_size / 2; n++) {
 466             fft_out[n].re *= scale;
 467             fft_out[n].im *= scale;
 468         }
 469
 470         for (int n = 0; n < s->win_size / 2; n++)
 471             magnitude[n] = hypotf(fft_out[n].re, fft_out[n].im);
 472
 473         if (s->measure & (MEASURE_MEAN | MEASURE_VARIANCE))
 474             stats->mean     = spectral_mean(magnitude, s->win_size / 2, in->sample_rate / 2);
 475         if (s->measure & MEASURE_VARIANCE)
 476             stats->variance = spectral_variance(magnitude, s->win_size / 2, in->sample_rate / 2, stats->mean);
 477         if (s->measure & (MEASURE_SPREAD | MEASURE_KURTOSIS | MEASURE_SKEWNESS | MEASURE_CENTROID))
 478             stats->centroid = spectral_centroid(magnitude, s->win_size / 2, in->sample_rate / 2);
 479         if (s->measure & (MEASURE_SPREAD | MEASURE_KURTOSIS | MEASURE_SKEWNESS))
 480             stats->spread   = spectral_spread(magnitude, s->win_size / 2, in->sample_rate / 2, stats->centroid);
 481         if (s->measure & MEASURE_SKEWNESS)
 482             stats->skewness = spectral_skewness(magnitude, s->win_size / 2, in->sample_rate / 2, stats->centroid, stats->spread);
 483         if (s->measure & MEASURE_KURTOSIS)
 484             stats->kurtosis = spectral_kurtosis(magnitude, s->win_size / 2, in->sample_rate / 2, stats->centroid, stats->spread);
 485         if (s->measure & MEASURE_ENTROPY)
 486             stats->entropy  = spectral_entropy(magnitude, s->win_size / 2, in->sample_rate / 2);
 487         if (s->measure & MEASURE_FLATNESS)
 488             stats->flatness = spectral_flatness(magnitude, s->win_size / 2, in->sample_rate / 2);
 489         if (s->measure & MEASURE_CREST)
 490             stats->crest    = spectral_crest(magnitude, s->win_size / 2, in->sample_rate / 2);
 491         if (s->measure & MEASURE_FLUX)
 492             stats->flux     = spectral_flux(magnitude, prev_magnitude, s->win_size / 2, in->sample_rate / 2);
 493         if (s->measure & MEASURE_SLOPE)
 494             stats->slope    = spectral_slope(magnitude, s->win_size / 2, in->sample_rate / 2);
 495         if (s->measure & MEASURE_DECREASE)
 496             stats->decrease = spectral_decrease(magnitude, s->win_size / 2, in->sample_rate / 2);
 497         if (s->measure & MEASURE_ROLLOFF)
 498             stats->rolloff  = spectral_rolloff(magnitude, s->win_size / 2, in->sample_rate / 2);
 499
 500         memcpy(prev_magnitude, magnitude, s->win_size * sizeof(float));
 501     }
 502
 503     return 0;
 504 }
 505
 506 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 507 {
 508     AVFilterContext *ctx = inlink->dst;
 509     AVFilterLink *outlink = ctx->outputs[0];
 510     AudioSpectralStatsContext *s = ctx->priv;
 511     AVDictionary **metadata;
 512     AVFrame *out;
 513     int ret;
 514
 515     if (av_frame_is_writable(in)) {
 516         out = in;
 517     } else {
 518         out = ff_get_audio_buffer(outlink, in->nb_samples);
 519         if (!out) {
 520             av_frame_free(&in);
 521             return AVERROR(ENOMEM);
 522         }
 523         ret = av_frame_copy_props(out, in);
 524         if (ret < 0)
 525             goto fail;
 526         ret = av_frame_copy(out, in);
 527         if (ret < 0)
 528             goto fail;
 529     }
 530
 531     metadata = &out->metadata;
 532     ff_filter_execute(ctx, filter_channel, in, NULL,
 533                       FFMIN(inlink->ch_layout.nb_channels, ff_filter_get_nb_threads(ctx)));
 534
 535     set_metadata(s, metadata);
 536
 537     if (out != in)
 538         av_frame_free(&in);
 539     return ff_filter_frame(outlink, out);
 540 fail:
 541     av_frame_free(&in);
 542     av_frame_free(&out);
 543     return ret;
 544 }
 545
 546 static int activate(AVFilterContext *ctx)
 547 {
 548     AudioSpectralStatsContext *s = ctx->priv;
 549     AVFilterLink *outlink = ctx->outputs[0];
 550     AVFilterLink *inlink = ctx->inputs[0];
 551     AVFrame *in;
 552     int ret;
 553
 554     FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
 555
 556     ret = ff_inlink_consume_samples(inlink, s->hop_size, s->hop_size, &in);
 557     if (ret < 0)
 558         return ret;
 559     if (ret > 0)
 560         ret = filter_frame(inlink, in);
 561     if (ret < 0)
 562         return ret;
 563
 564     if (ff_inlink_queued_samples(inlink) >= s->hop_size) {
 565         ff_filter_set_ready(ctx, 10);
 566         return 0;
 567     }
 568
 569     FF_FILTER_FORWARD_STATUS(inlink, outlink);
 570     FF_FILTER_FORWARD_WANTED(outlink, inlink);
 571
 572     return FFERROR_NOT_READY;
 573 }
 574
 575 static av_cold void uninit(AVFilterContext *ctx)
 576 {
 577     AudioSpectralStatsContext *s = ctx->priv;
 578
 579     for (int ch = 0; ch < s->nb_channels; ch++) {
 580         if (s->fft)
 581             av_tx_uninit(&s->fft[ch]);
 582         if (s->fft_in)
 583             av_freep(&s->fft_in[ch]);
 584         if (s->fft_out)
 585             av_freep(&s->fft_out[ch]);
 586         if (s->magnitude)
 587             av_freep(&s->magnitude[ch]);
 588         if (s->prev_magnitude)
 589             av_freep(&s->prev_magnitude[ch]);
 590     }
 591
 592     av_freep(&s->fft);
 593     av_freep(&s->magnitude);
 594     av_freep(&s->prev_magnitude);
 595     av_freep(&s->fft_in);
 596     av_freep(&s->fft_out);
 597     av_freep(&s->stats);
 598
 599     av_freep(&s->window_func_lut);
 600     av_frame_free(&s->window);
 601 }
 602
 603 static const AVFilterPad aspectralstats_outputs[] = {
 604     {
 605         .name         = "default",
 606         .type         = AVMEDIA_TYPE_AUDIO,
 607         .config_props = config_output,
 608     },
 609 };
 610
 611 const FFFilter ff_af_aspectralstats = {
 612     .p.name        = "aspectralstats",
 613     .p.description = NULL_IF_CONFIG_SMALL("Show frequency domain statistics about audio frames."),
 614     .p.priv_class  = &aspectralstats_class,
 615     .p.flags       = AVFILTER_FLAG_SLICE_THREADS,
 616     .priv_size     = sizeof(AudioSpectralStatsContext),
 617     .uninit        = uninit,
 618     .activate      = activate,
 619     FILTER_INPUTS(ff_audio_default_filterpad),
 620     FILTER_OUTPUTS(aspectralstats_outputs),
 621     FILTER_SINGLE_SAMPLEFMT(AV_SAMPLE_FMT_FLTP),
 622 };