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lavfi/af_aemphasis: remove unnecessary complex number usage

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complex is not available on all platforms. Furthermore, it is trivial to
rewrite complex number expressions to real arithmetic, and in fact
sometimes advantageous for performance reasons: by wrapping as a complex,
one forces a particular Cartesian representation that is not necessarily optimal for the purpose.

Configure dependencies also removed, and aemphasis is now available across
all platforms.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
This commit is contained in:
Ganesh Ajjanagadde 2015-12-21 17:12:04 -08:00
parent a0ec4aebab
commit 520a5d33f0
2 changed files with 6 additions and 8 deletions
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1
configure vendored
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@ -2836,7 +2836,6 @@ unix_protocol_deps="sys_un_h"
unix_protocol_select="network" unix_protocol_select="network"
# filters # filters
aemphasis_filter_deps="cabs cexp"
amovie_filter_deps="avcodec avformat" amovie_filter_deps="avcodec avformat"
aresample_filter_deps="swresample" aresample_filter_deps="swresample"
ass_filter_deps="libass" ass_filter_deps="libass"

13
libavfilter/af_aemphasis.c
View File

@ -18,8 +18,6 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/ */
#include <complex.h>
#include "libavutil/opt.h" #include "libavutil/opt.h"
#include "avfilter.h" #include "avfilter.h"
#include "internal.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) static double freq_gain(BiquadCoeffs *c, double freq, double sr)
{ {
double complex z, w; double zr, zi;
freq *= 2.0 * M_PI / sr; freq *= 2.0 * M_PI / sr;
w = 0 + I * freq; zr = cos(freq);
z = 1.0 / cexp(w); zi = -sin(freq);
return cabs(((double complex)c->a0 + c->a1 * z + c->a2 * z*z) / /* |(a0 + a1*z + a2*z^2)/(1 + b1*z + b2*z^2)| */
((double complex)1.0 + c->b1 * z + c->b2 * z*z)); 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) static int config_input(AVFilterLink *inlink)