diff options
| -rw-r--r-- | libao2/pl_eq.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/libao2/pl_eq.c b/libao2/pl_eq.c index 2588b383d1..eb9234a297 100644 --- a/libao2/pl_eq.c +++ b/libao2/pl_eq.c @@ -89,16 +89,21 @@ static int control(int cmd,int arg){ return CONTROL_UNKNOWN; } +// return rounded 16bit int +static inline int16_t lround16(double n){ + return (int16_t)((n)>=0.0?(n)+0.5:(n)-0.5); +} + // 2nd order Band-pass Filter design void bp2(int16_t* a, int16_t* b, float fc, float q){ double th=2*3.141592654*fc; double C=(1 - tan(th*q/2))/(1 + tan(th*q/2)); - a[0] = (int16_t)( 16383.0 * (1 + C) * cos(th) + 0.5); - a[1] = (int16_t)(-16383.0 * C + 0.5); + a[0] = lround16( 16383.0 * (1 + C) * cos(th)); + a[1] = lround16(-16383.0 * C); - b[0] = (int16_t)(-16383.0 * (C - 1)/2 + 0.5); - b[1] = (int16_t)(-16383.0 * 1.0050 + 0.5); + b[0] = lround16(-16383.0 * (C - 1)/2); + b[1] = lround16(-16383.0 * 1.0050); } // empty buffers |