avfilter/af_afftdn: use better approach for gain smoothing

Paul B Mahol committed 4 years ago

Commit fe85afb1 parent eae3b842 files · +30 −12Browse files

Unified · Split

2 files

doc/filters.texi +4 −3
libavfilter/af_afftdn.c +26 −9

@@ -1392,10 +1392,11 @@ Default value is @code{none}. · 1391 unmodified lines
1392	@end table	1392	@end table
1393		1393
1394	@item gain_smooth, gs	1394	@item gain_smooth, gs
1395	Set gain smooth factor, used to lowpass gains applied to each frequency bin.	1395	Set gain smooth spatial radius, used to smooth gains applied to each frequency bin.
1396	Useful to reduce random music noise artefacts.	1396	Useful to reduce random music noise artefacts.
1397	Higher values reduce smoothing of gains.	1397	Higher values increases smoothing of gains.
1398	Default value is @code{1.0}.	1398	Allowed range is from @code{0} to @code{50}.
		1399	Default value is @code{0}.
1399	@end table	1400	@end table
1400		1401
1401	@subsection Commands	1402	@subsection Commands

libavfilter/af_afftdn.c+26−9

     double     *band_amt;
     double     *band_excit;
     double     *gain;
+    double     *smoothed_gain;
     double     *prior;
     double     *prior_band_excit;
     double     *clean_data;
     int     output_mode;
     int     noise_floor_link;
     float   ratio;
-    float   gain_smooth;
+    int     gain_smooth;
     float   band_multiplier;
     float   floor_offset;
     {  "begin",   "start",                0,                       AV_OPT_TYPE_CONST,  {.i64 = SAMPLE_START},  0,  0, AFR, "sample" },
     {  "stop",    "stop",                 0,                       AV_OPT_TYPE_CONST,  {.i64 = SAMPLE_STOP},   0,  0, AFR, "sample" },
     {  "end",     "stop",                 0,                       AV_OPT_TYPE_CONST,  {.i64 = SAMPLE_STOP},   0,  0, AFR, "sample" },
-    { "gain_smooth", "set gain smooth factor",OFFSET(gain_smooth), AV_OPT_TYPE_FLOAT,  {.dbl = 1.00},     0.0001,  1, AFR },
+    { "gain_smooth", "set gain smooth radius",OFFSET(gain_smooth), AV_OPT_TYPE_INT,    {.i64 = 0},             0, 50, AFR },
-    { "gs",          "set gain smooth factor",OFFSET(gain_smooth), AV_OPT_TYPE_FLOAT,  {.dbl = 1.00},     0.0001,  1, AFR },
+    { "gs",          "set gain smooth radius",OFFSET(gain_smooth), AV_OPT_TYPE_INT,    {.i64 = 0},             0, 50, AFR },
     { NULL }
 };
     double *noisy_data = dnch->noisy_data;
     double *band_excit = dnch->band_excit;
     double *band_amt = dnch->band_amt;
+    double *smoothed_gain = dnch->smoothed_gain;
     double *gain = dnch->gain;
     for (int i = 0; i < s->bin_count; i++) {
         }
     }
-    {
+    memcpy(smoothed_gain, gain, s->bin_count * sizeof(*smoothed_gain));
-        const double f = s->gain_smooth;
+    if (s->gain_smooth > 0) {
-        const double F = 1. - f;
+        const int r = s->gain_smooth;
+        for (int i = r; i < s->bin_count - r; i++) {
+            const double gc = gain[i];
+            double num = 0., den = 0.;
+            for (int j = -r; j <= r; j++) {
+                const double g = gain[i + j];
+                const double d = 1. - fabs(g - gc);
-        for (int i = 1; i < s->bin_count; i++)
+                num += g * d;
-            gain[i] = gain[i-1] * F + f * gain[i];
+                den += d;
+            }
+            smoothed_gain[i] = num / den;
+        }
     }
     for (int i = 0; i < s->bin_count; i++) {
-        const double new_gain = gain[i];
+        const double new_gain = smoothed_gain[i];
         fft_data[i].re *= new_gain;
         fft_data[i].im *= new_gain;
         dnch->band_amt = av_calloc(s->number_of_bands, sizeof(*dnch->band_amt));
         dnch->band_excit = av_calloc(s->number_of_bands, sizeof(*dnch->band_excit));
         dnch->gain = av_calloc(s->bin_count, sizeof(*dnch->gain));
+        dnch->smoothed_gain = av_calloc(s->bin_count, sizeof(*dnch->smoothed_gain));
         dnch->prior = av_calloc(s->bin_count, sizeof(*dnch->prior));
         dnch->prior_band_excit = av_calloc(s->number_of_bands, sizeof(*dnch->prior_band_excit));
         dnch->clean_data = av_calloc(s->bin_count, sizeof(*dnch->clean_data));
             !dnch->band_amt ||
             !dnch->band_excit ||
             !dnch->gain ||
+            !dnch->smoothed_gain ||
             !dnch->prior ||
             !dnch->prior_band_excit ||
             !dnch->clean_data ||
             av_freep(&dnch->band_amt);
             av_freep(&dnch->band_excit);
             av_freep(&dnch->gain);
+            av_freep(&dnch->smoothed_gain);
             av_freep(&dnch->prior);
             av_freep(&dnch->prior_band_excit);
             av_freep(&dnch->clean_data);

avfilter/af_afftdn: use better approach for gain smoothing

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