@@ -284,7 +284,7 @@ OBJS-$(CONFIG_APHASEMETER_FILTER)            += avf_aphasemeter.o

 OBJS-$(CONFIG_AVECTORSCOPE_FILTER)           += avf_avectorscope.o

 OBJS-$(CONFIG_CONCAT_FILTER)                 += avf_concat.o

 OBJS-$(CONFIG_SHOWCQT_FILTER)                += avf_showcqt.o lswsutils.o lavfutils.o

-OBJS-$(CONFIG_SHOWFREQS_FILTER)              += avf_showfreqs.o

+OBJS-$(CONFIG_SHOWFREQS_FILTER)              += avf_showfreqs.o window_func.o

 OBJS-$(CONFIG_SHOWSPECTRUM_FILTER)           += avf_showspectrum.o

 OBJS-$(CONFIG_SHOWVOLUME_FILTER)             += avf_showvolume.o

 OBJS-$(CONFIG_SHOWWAVES_FILTER)              += avf_showwaves.o

@@ -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;

new file mode 100644

@@ -0,0 +1,110 @@

+/*

+ * Copyright (c) 2015 Paul B Mahol

+ *

+ * This file is part of FFmpeg.

+ *

+ * FFmpeg is free software; you can redistribute it and/or

+ * modify it under the terms of the GNU Lesser General Public

+ * License as published by the Free Software Foundation; either

+ * version 2.1 of the License, or (at your option) any later version.

+ *

+ * FFmpeg is distributed in the hope that it will be useful,

+ * but WITHOUT ANY WARRANTY; without even the implied warranty of

+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+ * Lesser General Public License for more details.

+ *

+ * You should have received a copy of the GNU Lesser General Public

+ * License along with FFmpeg; if not, write to the Free Software

+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+ */

+

+#include <math.h>

+

+#include "libavutil/avassert.h"

+#include "window_func.h"

+

+void ff_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);

+    }

+}

new file mode 100644

@@ -0,0 +1,32 @@

+/*

+ * Copyright (c) 2015 Paul B Mahol

+ *

+ * This file is part of FFmpeg.

+ *

+ * FFmpeg is free software; you can redistribute it and/or

+ * modify it under the terms of the GNU Lesser General Public

+ * License as published by the Free Software Foundation; either

+ * version 2.1 of the License, or (at your option) any later version.

+ *

+ * FFmpeg is distributed in the hope that it will be useful,

+ * but WITHOUT ANY WARRANTY; without even the implied warranty of

+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+ * Lesser General Public License for more details.

+ *

+ * You should have received a copy of the GNU Lesser General Public

+ * License along with FFmpeg; if not, write to the Free Software

+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+ */

+

+

+#ifndef AVFILTER_WINDOW_FUNC_H

+#define AVFILTER_WINDOW_FUNC_H

+

+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 };

+

+void ff_generate_window_func(float *lut, int N, int win_func, float *overlap);

+

+#endif /* AVFILTER_WINDOW_FUNC_H */