diff options
Diffstat (limited to 'libaf/filter.c')
| -rw-r--r-- | libaf/filter.c | 90 |
1 files changed, 0 insertions, 90 deletions
diff --git a/libaf/filter.c b/libaf/filter.c index c5ab039130..b272125fd8 100644 --- a/libaf/filter.c +++ b/libaf/filter.c @@ -46,51 +46,6 @@ inline FLOAT_TYPE af_filter_fir(register unsigned int n, const FLOAT_TYPE* w, return y; } -/* C implementation of parallel FIR filter y(k)=w(k) * x(k) (where * denotes convolution) - - n number of filter taps, where mod(n,4)==0 - d number of filters - xi current index in xq - w filter taps k by n big - x input signal must be a circular buffers which are indexed backwards - y output buffer - s output buffer stride -*/ -FLOAT_TYPE* af_filter_pfir(unsigned int n, unsigned int d, unsigned int xi, - const FLOAT_TYPE** w, const FLOAT_TYPE** x, FLOAT_TYPE* y, - unsigned int s) -{ - register const FLOAT_TYPE* xt = *x + xi; - register const FLOAT_TYPE* wt = *w; - register int nt = 2*n; - while(d-- > 0){ - *y = af_filter_fir(n,wt,xt); - wt+=n; - xt+=nt; - y+=s; - } - return y; -} - -/* Add new data to circular queue designed to be used with a parallel - FIR filter, with d filters. xq is the circular queue, in pointing - 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, - FLOAT_TYPE** xq, const FLOAT_TYPE* in, unsigned int s) -{ - register FLOAT_TYPE* txq = *xq + xi; - register int nt = n*2; - - while(d-- >0){ - *txq= *(txq+n) = *in; - txq+=nt; - in+=s; - } - return (++xi)&(n-1); -} - /****************************************************************************** * FIR filter design ******************************************************************************/ @@ -234,51 +189,6 @@ int af_filter_design_fir(unsigned int n, FLOAT_TYPE* w, const FLOAT_TYPE* fc, return 0; } -/* Design polyphase FIR filter from prototype filter - - n length of prototype filter - k number of polyphase components - w prototype filter taps - pw Parallel FIR filter - g Filter gain - flags FWD forward indexing - REW reverse indexing - ODD multiply every 2nd filter tap by -1 => HP filter - - returns 0 if OK, -1 if fail -*/ -int af_filter_design_pfir(unsigned int n, unsigned int k, const 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; - FLOAT_TYPE t; // g * w[i] - - // Sanity check - if(l<1 || k<1 || !w || !pw) - return -1; - - // Do the stuff - if(flags&REW){ - for(j=l-1;j>-1;j--){//Columns - for(i=0;i<(int)k;i++){//Rows - t=g * *w++; - pw[i][j]=t * ((flags & ODD) ? ((j & 1) ? -1 : 1) : 1); - } - } - } - else{ - for(j=0;j<l;j++){//Columns - for(i=0;i<(int)k;i++){//Rows - t=g * *w++; - pw[i][j]=t * ((flags & ODD) ? ((j & 1) ? 1 : -1) : 1); - } - } - } - return -1; -} - /****************************************************************************** * IIR filter design ******************************************************************************/ |