avfilter: move window function generation into separate file

Signed-off-by: Paul B Mahol <onemda@gmail.com>

1 files changed, 2 insertions, 91 deletions

diff --git a/libavfilter/avf_showfreqs.c b/libavfilter/avf_showfreqs.c
index df3fcd1dc0..03fcf4e3a9 100644
--- a/libavfilter/avf_showfreqs.c
+++ b/libavfilter/avf_showfreqs.c
@@ -32,15 +32,12 @@
 #include "video.h"
 #include "avfilter.h"
 #include "internal.h"
+#include "window_func.h"
 
 enum DisplayMode    { LINE, BAR, DOT, NB_MODES };
 enum ChannelMode    { COMBINED, SEPARATE, NB_CMODES };
 enum FrequencyScale { FS_LINEAR, FS_LOG, FS_RLOG, NB_FSCALES };
 enum AmplitudeScale { AS_LINEAR, AS_SQRT, AS_CBRT, AS_LOG, NB_ASCALES };
-enum WindowFunc     { WFUNC_RECT, WFUNC_HANNING, WFUNC_HAMMING, WFUNC_BLACKMAN,
-                      WFUNC_BARTLETT, WFUNC_WELCH, WFUNC_FLATTOP,
-                      WFUNC_BHARRIS, WFUNC_BNUTTALL, WFUNC_SINE, WFUNC_NUTTALL,
-                      WFUNC_BHANN, WFUNC_LANCZOS, WFUNC_GAUSS, NB_WFUNC };
 
 typedef struct ShowFreqsContext {
     const AVClass *class;
@@ -156,92 +153,6 @@ static int query_formats(AVFilterContext *ctx)
     return 0;
 }
 
-static void generate_window_func(float *lut, int N, int win_func, float *overlap)
-{
-    int n;
-
-    switch (win_func) {
-    case WFUNC_RECT:
-        for (n = 0; n < N; n++)
-            lut[n] = 1.;
-        *overlap = 0.;
-        break;
-    case WFUNC_BARTLETT:
-        for (n = 0; n < N; n++)
-            lut[n] = 1.-fabs((n-(N-1)/2.)/((N-1)/2.));
-        *overlap = 0.5;
-        break;
-    case WFUNC_HANNING:
-        for (n = 0; n < N; n++)
-            lut[n] = .5*(1-cos(2*M_PI*n/(N-1)));
-        *overlap = 0.5;
-        break;
-    case WFUNC_HAMMING:
-        for (n = 0; n < N; n++)
-            lut[n] = .54-.46*cos(2*M_PI*n/(N-1));
-        *overlap = 0.5;
-        break;
-    case WFUNC_BLACKMAN:
-        for (n = 0; n < N; n++)
-            lut[n] = .42659-.49656*cos(2*M_PI*n/(N-1))+.076849*cos(4*M_PI*n/(N-1));
-        *overlap = 0.661;
-        break;
-    case WFUNC_WELCH:
-        for (n = 0; n < N; n++)
-            lut[n] = 1.-(n-(N-1)/2.)/((N-1)/2.)*(n-(N-1)/2.)/((N-1)/2.);
-        *overlap = 0.293;
-        break;
-    case WFUNC_FLATTOP:
-        for (n = 0; n < N; n++)
-            lut[n] = 1.-1.985844164102*cos( 2*M_PI*n/(N-1))+1.791176438506*cos( 4*M_PI*n/(N-1))-
-                        1.282075284005*cos( 6*M_PI*n/(N-1))+0.667777530266*cos( 8*M_PI*n/(N-1))-
-                        0.240160796576*cos(10*M_PI*n/(N-1))+0.056656381764*cos(12*M_PI*n/(N-1))-
-                        0.008134974479*cos(14*M_PI*n/(N-1))+0.000624544650*cos(16*M_PI*n/(N-1))-
-                        0.000019808998*cos(18*M_PI*n/(N-1))+0.000000132974*cos(20*M_PI*n/(N-1));
-        *overlap = 0.841;
-        break;
-    case WFUNC_BHARRIS:
-        for (n = 0; n < N; n++)
-            lut[n] = 0.35875-0.48829*cos(2*M_PI*n/(N-1))+0.14128*cos(4*M_PI*n/(N-1))-0.01168*cos(6*M_PI*n/(N-1));
-        *overlap = 0.661;
-        break;
-    case WFUNC_BNUTTALL:
-        for (n = 0; n < N; n++)
-            lut[n] = 0.3635819-0.4891775*cos(2*M_PI*n/(N-1))+0.1365995*cos(4*M_PI*n/(N-1))-0.0106411*cos(6*M_PI*n/(N-1));
-        *overlap = 0.661;
-        break;
-    case WFUNC_BHANN:
-        for (n = 0; n < N; n++)
-            lut[n] = 0.62-0.48*fabs(n/(double)(N-1)-.5)-0.38*cos(2*M_PI*n/(N-1));
-        *overlap = 0.5;
-        break;
-    case WFUNC_SINE:
-        for (n = 0; n < N; n++)
-            lut[n] = sin(M_PI*n/(N-1));
-        *overlap = 0.75;
-        break;
-    case WFUNC_NUTTALL:
-        for (n = 0; n < N; n++)
-            lut[n] = 0.355768-0.487396*cos(2*M_PI*n/(N-1))+0.144232*cos(4*M_PI*n/(N-1))-0.012604*cos(6*M_PI*n/(N-1));
-        *overlap = 0.663;
-        break;
-    case WFUNC_LANCZOS:
-#define SINC(x) (!(x)) ? 1 : sin(M_PI * (x))/(M_PI * (x));
-        for (n = 0; n < N; n++)
-            lut[n] = SINC((2.*n)/(N-1)-1);
-        *overlap = 0.75;
-        break;
-    case WFUNC_GAUSS:
-#define SQR(x) ((x)*(x))
-        for (n = 0; n < N; n++)
-            lut[n] = exp(-0.5 * SQR((n-(N-1)/2)/(0.4*(N-1)/2.f)));
-        *overlap = 0.75;
-        break;
-    default:
-        av_assert0(0);
-    }
-}
-
 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
@@ -290,7 +201,7 @@ static int config_output(AVFilterLink *outlink)
                                       sizeof(*s->window_func_lut));
     if (!s->window_func_lut)
         return AVERROR(ENOMEM);
-    generate_window_func(s->window_func_lut, s->win_size, s->win_func, &overlap);
+    ff_generate_window_func(s->window_func_lut, s->win_size, s->win_func, &overlap);
     if (s->overlap == 1.)
         s->overlap = overlap;
     s->skip_samples = (1. - s->overlap) * s->win_size;