- iir->biquads[current_biquad].a0 = 1.0;
- iir->biquads[current_biquad].a1 = a[2] / a[4];
- iir->biquads[current_biquad].a2 = a[0] / a[4];
- iir->biquads[current_biquad].b0 = b[4] / a[4] * (current_biquad ? 1.0 : iir->g);
- iir->biquads[current_biquad].b1 = b[2] / a[4] * (current_biquad ? 1.0 : iir->g);
- iir->biquads[current_biquad].b2 = b[0] / a[4] * (current_biquad ? 1.0 : iir->g);
-
- av_log(ctx, AV_LOG_VERBOSE, "a=%lf %lf %lf:b=%lf %lf %lf\n",
- iir->biquads[current_biquad].a0,
- iir->biquads[current_biquad].a1,
- iir->biquads[current_biquad].a2,
- iir->biquads[current_biquad].b0,
- iir->biquads[current_biquad].b1,
- iir->biquads[current_biquad].b2);
+ iir->biquads[current_biquad].a[0] = 1.;
+ iir->biquads[current_biquad].a[1] = a[2] / a[4];
+ iir->biquads[current_biquad].a[2] = a[0] / a[4];
+ iir->biquads[current_biquad].b[0] = b[4] / a[4];
+ iir->biquads[current_biquad].b[1] = b[2] / a[4];
+ iir->biquads[current_biquad].b[2] = b[0] / a[4];
+
+ if (fabs(iir->biquads[current_biquad].b[0] +
+ iir->biquads[current_biquad].b[1] +
+ iir->biquads[current_biquad].b[2]) > 1e-6) {
+ factor = (iir->biquads[current_biquad].a[0] +
+ iir->biquads[current_biquad].a[1] +
+ iir->biquads[current_biquad].a[2]) /
+ (iir->biquads[current_biquad].b[0] +
+ iir->biquads[current_biquad].b[1] +
+ iir->biquads[current_biquad].b[2]);
+
+ av_log(ctx, AV_LOG_VERBOSE, "factor=%f\n", factor);
+
+ iir->biquads[current_biquad].b[0] *= factor;
+ iir->biquads[current_biquad].b[1] *= factor;
+ iir->biquads[current_biquad].b[2] *= factor;
+ }
+
+ iir->biquads[current_biquad].b[0] *= (current_biquad ? 1.0 : iir->g);
+ iir->biquads[current_biquad].b[1] *= (current_biquad ? 1.0 : iir->g);
+ iir->biquads[current_biquad].b[2] *= (current_biquad ? 1.0 : iir->g);
+
+ av_log(ctx, AV_LOG_VERBOSE, "a=%f %f %f:b=%f %f %f\n",
+ iir->biquads[current_biquad].a[0],
+ iir->biquads[current_biquad].a[1],
+ iir->biquads[current_biquad].a[2],
+ iir->biquads[current_biquad].b[0],
+ iir->biquads[current_biquad].b[1],
+ iir->biquads[current_biquad].b[2]);