select more sensible default windows (= attenuation beyond the dynamic range of your...

[ffmpeg] / libavcodec / resample2.c

diff --git a/libavcodec/resample2.c b/libavcodec/resample2.c
index 6f487bfd95af23cde39184b93108d067ae747746..ebda7e5a8ba1c82c782c5c739992d394a7e285e2 100644 (file)
--- a/libavcodec/resample2.c
+++ b/libavcodec/resample2.c
@@ -30,13 +30,14 @@
 #include "common.h"
 #include "dsputil.h"
 
-#if 1
+#ifndef CONFIG_RESAMPLE_HP
 #define FILTER_SHIFT 15
 
 #define FELEM int16_t
 #define FELEM2 int32_t
 #define FELEM_MAX INT16_MAX
 #define FELEM_MIN INT16_MIN
+#define WINDOW_TYPE 9
 #else
 #define FILTER_SHIFT 30
 
@@ -44,6 +45,7 @@
 #define FELEM2 int64_t
 #define FELEM_MAX INT32_MAX
 #define FELEM_MIN INT32_MIN
+#define WINDOW_TYPE 12
 #endif
 
 
@@ -80,7 +82,7 @@ static double bessel(double x){
  * builds a polyphase filterbank.
  * @param factor resampling factor
  * @param scale wanted sum of coefficients for each filter
- * @param type 0->cubic, 1->blackman nuttall windowed sinc, 2->kaiser windowed sinc beta=16
+ * @param type 0->cubic, 1->blackman nuttall windowed sinc, 2..16->kaiser windowed sinc beta=2..16
  */
 void av_build_filter(FELEM *filter, double factor, int tap_count, int phase_count, int scale, int type){
     int ph, i, v;
@@ -108,9 +110,9 @@ void av_build_filter(FELEM *filter, double factor, int tap_count, int phase_coun
                 w = 2.0*x / (factor*tap_count) + M_PI;
                 y *= 0.3635819 - 0.4891775 * cos(w) + 0.1365995 * cos(2*w) - 0.0106411 * cos(3*w);
                 break;
-            case 2:
+            default:
                 w = 2.0*x / (factor*tap_count*M_PI);
-                y *= bessel(16*sqrt(FFMAX(1-w*w, 0)));
+                y *= bessel(type*sqrt(FFMAX(1-w*w, 0)));
                 break;
             }
 
@@ -177,7 +179,7 @@ AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_size,
 
     c->filter_length= FFMAX((int)ceil(filter_size/factor), 1);
     c->filter_bank= av_mallocz(c->filter_length*(phase_count+1)*sizeof(FELEM));
-    av_build_filter(c->filter_bank, factor, c->filter_length, phase_count, 1<<FILTER_SHIFT, 1);
+    av_build_filter(c->filter_bank, factor, c->filter_length, phase_count, 1<<FILTER_SHIFT, WINDOW_TYPE);
     memcpy(&c->filter_bank[c->filter_length*phase_count+1], c->filter_bank, (c->filter_length-1)*sizeof(FELEM));
     c->filter_bank[c->filter_length*phase_count]= c->filter_bank[c->filter_length - 1];