diff options
Diffstat (limited to 'libavfilter/af_aemphasis.c')
| -rw-r--r-- | libavfilter/af_aemphasis.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/libavfilter/af_aemphasis.c b/libavfilter/af_aemphasis.c index 2966f7721f..a5b8e3058a 100644 --- a/libavfilter/af_aemphasis.c +++ b/libavfilter/af_aemphasis.c @@ -18,8 +18,6 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ -#include <complex.h> - #include "libavutil/opt.h" #include "avfilter.h" #include "internal.h" @@ -189,14 +187,15 @@ static inline void set_lp_rbj(BiquadD2 *bq, double fc, double q, double sr, doub static double freq_gain(BiquadCoeffs *c, double freq, double sr) { - double complex z, w; + double zr, zi; freq *= 2.0 * M_PI / sr; - w = 0 + I * freq; - z = 1.0 / cexp(w); + zr = cos(freq); + zi = -sin(freq); - return cabs(((double complex)c->a0 + c->a1 * z + c->a2 * z*z) / - ((double complex)1.0 + c->b1 * z + c->b2 * z*z)); + /* |(a0 + a1*z + a2*z^2)/(1 + b1*z + b2*z^2)| */ + return hypot(c->a0 + c->a1*zr + c->a2*(zr*zr-zi*zi), c->a1*zi + 2*c->a2*zr*zi) / + hypot(1 + c->b1*zr + c->b2*(zr*zr-zi*zi), c->b1*zi + 2*c->b2*zr*zi); } static int config_input(AVFilterLink *inlink) |