diff options
| -rw-r--r-- | libswresample/resample.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libswresample/resample.c b/libswresample/resample.c index c881ed8f41..6f2ca982ea 100644 --- a/libswresample/resample.c +++ b/libswresample/resample.c @@ -73,7 +73,7 @@ static double bessel(double x){ static int build_filter(ResampleContext *c, void *filter, double factor, int tap_count, int alloc, int phase_count, int scale, int filter_type, int kaiser_beta){ int ph, i; - double x, y, w; + double x, y, w, t; double *tab = av_malloc_array(tap_count+1, sizeof(*tab)); const int center= (tap_count-1)/2; @@ -100,7 +100,8 @@ static int build_filter(ResampleContext *c, void *filter, double factor, int tap break;} case SWR_FILTER_TYPE_BLACKMAN_NUTTALL: 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); + t = cos(w); + y *= 0.3635819 - 0.4891775 * t + 0.1365995 * (2*t*t-1) - 0.0106411 * (4*t*t*t - 3*t); break; case SWR_FILTER_TYPE_KAISER: w = 2.0*x / (factor*tap_count*M_PI); |