diff options
Diffstat (limited to 'libaf/filter.c')
-rw-r--r-- | libaf/filter.c | 66 |
1 files changed, 37 insertions, 29 deletions
diff --git a/libaf/filter.c b/libaf/filter.c index c9514edfe1..a6436b4108 100644 --- a/libaf/filter.c +++ b/libaf/filter.c @@ -25,9 +25,10 @@ w filter taps x input signal must be a circular buffer which is indexed backwards */ -inline _ftype_t af_filter_fir(register unsigned int n, _ftype_t* w, _ftype_t* x) +inline FLOAT_TYPE af_filter_fir(register unsigned int n, FLOAT_TYPE* w, + FLOAT_TYPE* x) { - register _ftype_t y; // Output + register FLOAT_TYPE y; // Output y = 0.0; do{ n--; @@ -46,10 +47,12 @@ inline _ftype_t af_filter_fir(register unsigned int n, _ftype_t* w, _ftype_t* x) y output buffer s output buffer stride */ -_ftype_t* af_filter_pfir(unsigned int n, unsigned int d, unsigned int xi, _ftype_t** w, _ftype_t** x, _ftype_t* y, unsigned int s) +FLOAT_TYPE* af_filter_pfir(unsigned int n, unsigned int d, unsigned int xi, + FLOAT_TYPE** w, FLOAT_TYPE** x, FLOAT_TYPE* y, + unsigned int s) { - register _ftype_t* xt = *x + xi; - register _ftype_t* wt = *w; + register FLOAT_TYPE* xt = *x + xi; + register FLOAT_TYPE* wt = *w; register int nt = 2*n; while(d-- > 0){ *y = af_filter_fir(n,wt,xt); @@ -65,9 +68,10 @@ _ftype_t* af_filter_pfir(unsigned int n, unsigned int d, unsigned int xi, _ftype at the new samples, xi current index in xq and n the length of the filter. xq must be n*2 by k big, s is the index for in. */ -int af_filter_updatepq(unsigned int n, unsigned int d, unsigned int xi, _ftype_t** xq, _ftype_t* in, unsigned int s) +int af_filter_updatepq(unsigned int n, unsigned int d, unsigned int xi, + FLOAT_TYPE** xq, FLOAT_TYPE* in, unsigned int s) { - register _ftype_t* txq = *xq + xi; + register FLOAT_TYPE* txq = *xq + xi; register int nt = n*2; while(d-- >0){ @@ -95,18 +99,19 @@ int af_filter_updatepq(unsigned int n, unsigned int d, unsigned int xi, _ftype_t returns 0 if OK, -1 if fail */ -int af_filter_design_fir(unsigned int n, _ftype_t* w, _ftype_t* fc, unsigned int flags, _ftype_t opt) +int af_filter_design_fir(unsigned int n, FLOAT_TYPE* w, FLOAT_TYPE* fc, + unsigned int flags, FLOAT_TYPE opt) { unsigned int o = n & 1; // Indicator for odd filter length unsigned int end = ((n + 1) >> 1) - o; // Loop end unsigned int i; // Loop index - _ftype_t k1 = 2 * M_PI; // 2*pi*fc1 - _ftype_t k2 = 0.5 * (_ftype_t)(1 - o);// Constant used if the filter has even length - _ftype_t k3; // 2*pi*fc2 Constant used in BP and BS design - _ftype_t g = 0.0; // Gain - _ftype_t t1,t2,t3; // Temporary variables - _ftype_t fc1,fc2; // Cutoff frequencies + FLOAT_TYPE k1 = 2 * M_PI; // 2*pi*fc1 + FLOAT_TYPE k2 = 0.5 * (FLOAT_TYPE)(1 - o);// Constant used if the filter has even length + FLOAT_TYPE k3; // 2*pi*fc2 Constant used in BP and BS design + FLOAT_TYPE g = 0.0; // Gain + FLOAT_TYPE t1,t2,t3; // Temporary variables + FLOAT_TYPE fc1,fc2; // Cutoff frequencies // Sanity check if(!w || (n == 0)) return -1; @@ -150,7 +155,7 @@ int af_filter_design_fir(unsigned int n, _ftype_t* w, _ftype_t* fc, unsigned int // Create filter for (i=0 ; i<end ; i++){ - t1 = (_ftype_t)(i+1) - k2; + t1 = (FLOAT_TYPE)(i+1) - k2; w[end-i-1] = w[n-end+i] = w[end-i-1] * sin(k1 * t1)/(M_PI * t1); // Sinc g += 2*w[end-i-1]; // Total gain in filter } @@ -163,7 +168,7 @@ int af_filter_design_fir(unsigned int n, _ftype_t* w, _ftype_t* fc, unsigned int // Create filter for (i=0 ; i<end ; i++){ - t1 = (_ftype_t)(i+1); + t1 = (FLOAT_TYPE)(i+1); w[end-i-1] = w[n-end+i] = -1 * w[end-i-1] * sin(k1 * t1)/(M_PI * t1); // Sinc g += ((i&1) ? (2*w[end-i-1]) : (-2*w[end-i-1])); // Total gain in filter } @@ -188,7 +193,7 @@ int af_filter_design_fir(unsigned int n, _ftype_t* w, _ftype_t* fc, unsigned int // Create filter for (i=0 ; i<end ; i++){ - t1 = (_ftype_t)(i+1) - k2; + t1 = (FLOAT_TYPE)(i+1) - k2; t2 = sin(k3 * t1)/(M_PI * t1); // Sinc fc2 t3 = sin(k1 * t1)/(M_PI * t1); // Sinc fc1 g += w[end-i-1] * (t3 + t2); // Total gain in filter @@ -203,7 +208,7 @@ int af_filter_design_fir(unsigned int n, _ftype_t* w, _ftype_t* fc, unsigned int // Create filter for (i=0 ; i<end ; i++){ - t1 = (_ftype_t)(i+1); + t1 = (FLOAT_TYPE)(i+1); t2 = sin(k1 * t1)/(M_PI * t1); // Sinc fc1 t3 = sin(k3 * t1)/(M_PI * t1); // Sinc fc2 w[end-i-1] = w[n-end+i] = w[end-i-1] * (t2 - t3); @@ -233,12 +238,13 @@ int af_filter_design_fir(unsigned int n, _ftype_t* w, _ftype_t* fc, unsigned int returns 0 if OK, -1 if fail */ -int af_filter_design_pfir(unsigned int n, unsigned int k, _ftype_t* w, _ftype_t** pw, _ftype_t g, unsigned int flags) +int af_filter_design_pfir(unsigned int n, unsigned int k, FLOAT_TYPE* w, + FLOAT_TYPE** pw, FLOAT_TYPE g, unsigned int flags) { int l = (int)n/k; // Length of individual FIR filters int i; // Counters int j; - _ftype_t t; // g * w[i] + FLOAT_TYPE t; // g * w[i] // Sanity check if(l<1 || k<1 || !w || !pw) @@ -274,9 +280,9 @@ int af_filter_design_pfir(unsigned int n, unsigned int k, _ftype_t* w, _ftype_t* Note that a0 is assumed to be 1, so there is no wrapping of it. */ -static void af_filter_prewarp(_ftype_t* a, _ftype_t fc, _ftype_t fs) +static void af_filter_prewarp(FLOAT_TYPE* a, FLOAT_TYPE fc, FLOAT_TYPE fs) { - _ftype_t wp; + FLOAT_TYPE wp; wp = 2.0 * fs * tan(M_PI * fc / fs); a[2] = a[2]/(wp * wp); a[1] = a[1]/wp; @@ -310,9 +316,10 @@ static void af_filter_prewarp(_ftype_t* a, _ftype_t fc, _ftype_t fs) Return: On return, set coef z-domain coefficients and k to the gain required to maintain overall gain = 1.0; */ -static void af_filter_bilinear(_ftype_t* a, _ftype_t* b, _ftype_t* k, _ftype_t fs, _ftype_t *coef) +static void af_filter_bilinear(FLOAT_TYPE* a, FLOAT_TYPE* b, FLOAT_TYPE* k, + FLOAT_TYPE fs, FLOAT_TYPE *coef) { - _ftype_t ad, bd; + FLOAT_TYPE ad, bd; /* alpha (Numerator in s-domain) */ ad = 4. * a[2] * fs * fs + 2. * a[1] * fs + a[0]; @@ -410,16 +417,17 @@ static void af_filter_bilinear(_ftype_t* a, _ftype_t* b, _ftype_t* k, _ftype_t f return -1 if fail 0 if success. */ -int af_filter_szxform(_ftype_t* a, _ftype_t* b, _ftype_t Q, _ftype_t fc, _ftype_t fs, _ftype_t *k, _ftype_t *coef) +int af_filter_szxform(FLOAT_TYPE* a, FLOAT_TYPE* b, FLOAT_TYPE Q, FLOAT_TYPE fc, + FLOAT_TYPE fs, FLOAT_TYPE *k, FLOAT_TYPE *coef) { - _ftype_t at[3]; - _ftype_t bt[3]; + FLOAT_TYPE at[3]; + FLOAT_TYPE bt[3]; if(!a || !b || !k || !coef || (Q>1000.0 || Q< 1.0)) return -1; - memcpy(at,a,3*sizeof(_ftype_t)); - memcpy(bt,b,3*sizeof(_ftype_t)); + memcpy(at,a,3*sizeof(FLOAT_TYPE)); + memcpy(bt,b,3*sizeof(FLOAT_TYPE)); bt[1]/=Q; |