char *a_str, *b_str, *g_str;
double dry_gain, wet_gain;
double mix;
+ int normalize;
int format;
int process;
int precision;
return 0;
}
+static void normalize_coeffs(AVFilterContext *ctx, int ch)
+{
+ AudioIIRContext *s = ctx->priv;
+ IIRChannel *iir = &s->iir[ch];
+ double sum_den = 0.;
+
+ if (!s->normalize)
+ return;
+
+ for (int i = 0; i < iir->nb_ab[1]; i++) {
+ sum_den += iir->ab[1][i];
+ }
+
+ if (sum_den > 1e-6) {
+ double factor, sum_num = 0.;
+
+ for (int i = 0; i < iir->nb_ab[0]; i++) {
+ sum_num += iir->ab[0][i];
+ }
+
+ factor = sum_num / sum_den;
+
+ for (int i = 0; i < iir->nb_ab[1]; i++) {
+ iir->ab[1][i] *= factor;
+ }
+ }
+}
+
static int convert_zp2tf(AVFilterContext *ctx, int channels)
{
AudioIIRContext *s = ctx->priv;
}
iir->nb_ab[0]++;
+ normalize_coeffs(ctx, ch);
+
fail:
av_free(topc);
av_free(botc);
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] +
+ if (s->normalize &&
+ 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] +
for (i = 0; i < iir->nb_ab[1]; i++) {
iir->ab[1][i] *= iir->g / iir->ab[0][0];
}
+
+ normalize_coeffs(ctx, ch);
}
switch (inlink->format) {
{ "flt", "single-precision floating-point", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, AF, "precision" },
{ "i32", "32-bit integers", 0, AV_OPT_TYPE_CONST, {.i64=2}, 0, 0, AF, "precision" },
{ "i16", "16-bit integers", 0, AV_OPT_TYPE_CONST, {.i64=3}, 0, 0, AF, "precision" },
+ { "n", "normalize coefficients", OFFSET(normalize),AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, AF },
{ "mix", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, AF },
{ "response", "show IR frequency response", OFFSET(response), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, VF },
{ "channel", "set IR channel to display frequency response", OFFSET(ir_channel), AV_OPT_TYPE_INT, {.i64=0}, 0, 1024, VF },