avfilter/af_biquads: fix low/highshelf 'k' calculation

3 years ago · 93b31dae1d
parent f912cefb83
commit 93b31dae1d
1 changed files with 2 additions and 2 deletions
--- a/libavfilter/af_biquads.c
+++ b/libavfilter/af_biquads.c
@ -690,7 +690,7 @@ static void convert_dir2zdf(BiquadsContext *s, int sample_rate)
    case lowshelf:
        A = ff_exp10(s->gain / 40.);
        g = tan(M_PI * s->frequency / sample_rate) / sqrt(A);
-        k = 1. / (Q * A);
+        k = 1. / Q;
        a[0] = 1. / (1. + g * (g + k));
        a[1] = g * a[0];
        a[2] = g * a[1];
@ -702,7 +702,7 @@ static void convert_dir2zdf(BiquadsContext *s, int sample_rate)
    case highshelf:
        A = ff_exp10(s->gain / 40.);
        g = tan(M_PI * s->frequency / sample_rate) / sqrt(A);
-        k = 1. / (Q * A);
+        k = 1. / Q;
        a[0] = 1. / (1. + g * (g + k));
        a[1] = g * a[0];
        a[2] = g * a[1];