commit db48d6e1decfc6dc60c83a8b95642534ac4da9fa
parent 985afb255c63bea69dcb5a7c4ae4713eb9411810
Author: fundamental <[email protected]>
Date: Thu, 6 Aug 2015 18:29:51 -0400
Fix EQ Filter View
Collect biquad parameters rather than the convolution of them.
This avoids numeric issues which can't be fixed by upgrading floats
to doubles.
Partial fix to bug #85
Diffstat:
6 files changed, 30 insertions(+), 37 deletions(-)
diff --git a/src/Effects/EQ.cpp b/src/Effects/EQ.cpp
@@ -205,41 +205,26 @@ float EQ::getfreqresponse(float freq)
return rap2dB(resp * outvolume);
}
-//full taps & three filter taps
-static void convolve(float *a, const float *filter)
-{
- float tmp[MAX_EQ_BANDS*2+1];
-
- for(int i=0; i<MAX_EQ_BANDS*2+1; ++i)
- tmp[i] = a[i];
-
- //Base Case
- a[0] = tmp[0]*filter[0];
- a[1] = tmp[0]*filter[1] + tmp[1]*filter[0];
-
- for(int i=2; i<MAX_EQ_BANDS+1; ++i) {
- a[i] = filter[0]*tmp[i] +
- filter[1]*tmp[i-1] +
- filter[2]*tmp[i-2];
- }
-}
-
//Not exactly the most efficient manner to derive the total taps, but it should
//be fast enough in practice
void EQ::getFilter(float *a, float *b) const
{
a[0] = 1;
b[0] = 1;
+ off_t off=0;
for(int i = 0; i < MAX_EQ_BANDS; ++i) {
auto &F = filter[i];
if(F.Ptype == 0)
continue;
- float Fb[3] = {F.l->coeff.c[0], F.l->coeff.c[1], F.l->coeff.c[2]};
- float Fa[3] = {1.0f, -F.l->coeff.d[1], -F.l->coeff.d[2]};
+ const double Fb[3] = {F.l->coeff.c[0], F.l->coeff.c[1], F.l->coeff.c[2]};
+ const double Fa[3] = {1.0f, -F.l->coeff.d[1], -F.l->coeff.d[2]};
for(int j=0; j<F.Pstages+1; ++j) {
- convolve(b, Fb);
- convolve(a, Fa);
+ for(int k=0; k<3; ++k) {
+ a[off] = Fa[k];
+ b[off] = Fb[k];
+ off++;
+ }
}
}
}
diff --git a/src/Effects/EQ.h b/src/Effects/EQ.h
@@ -38,8 +38,8 @@ class EQ:public Effect
void cleanup(void);
float getfreqresponse(float freq);
- void getFilter(float *a/*[MAX_EQ_BANDS*MAX_FILTER_STAGES*2+1]*/,
- float *b/*[MAX_EQ_BANDS*MAX_FILTER_STAGES*2+1]*/) const;
+ void getFilter(float *a/*[MAX_EQ_BANDS*MAX_FILTER_STAGES*3]*/,
+ float *b/*[MAX_EQ_BANDS*MAX_FILTER_STAGES*3]*/) const;
private:
//Parameters
unsigned char Pvolume;
diff --git a/src/Effects/EffectMgr.cpp b/src/Effects/EffectMgr.cpp
@@ -75,8 +75,8 @@ static const rtosc::Ports local_ports = {
if(eff->nefx != 7)
return;
EQ *eq = (EQ*)eff->efx;
- float a[MAX_EQ_BANDS*MAX_FILTER_STAGES*2+1];
- float b[MAX_EQ_BANDS*MAX_FILTER_STAGES*2+1];
+ float a[MAX_EQ_BANDS*MAX_FILTER_STAGES*3];
+ float b[MAX_EQ_BANDS*MAX_FILTER_STAGES*3];
memset(a, 0, sizeof(a));
memset(b, 0, sizeof(b));
eq->getFilter(a,b);
diff --git a/src/UI/EffUI.fl b/src/UI/EffUI.fl
@@ -943,7 +943,7 @@ stagescounter->oscMove("parameter"+to_s(npb+4));}
Fl_Counter stagescounter {
label {St.}
callback {eqgraph->update();}
- tooltip {Additional filter stages} xywh {340 60 30 15} type Simple labelfont 1 labelsize 10 minimum 1 maximum 127 step 1 textfont 1 textsize 11
+ tooltip {Additional filter stages} xywh {340 60 30 15} type Simple labelfont 1 labelsize 10 minimum 0 maximum 127 step 1 textfont 1 textsize 11
code0 {o->init("parameter14");}
class Fl_Osc_Counter
}
diff --git a/src/UI/Fl_EQGraph.H b/src/UI/Fl_EQGraph.H
@@ -24,6 +24,6 @@ class Fl_EQGraph:public Fl_Box, public Fl_Osc_Widget
float getfreqpos(float freq) const;
float samplerate;
- float num[MAX_EQ_BANDS*MAX_FILTER_STAGES*2+1];
- float dem[MAX_EQ_BANDS*MAX_FILTER_STAGES*2+1];
+ float num[MAX_EQ_BANDS*MAX_FILTER_STAGES*3];
+ float dem[MAX_EQ_BANDS*MAX_FILTER_STAGES*3];
};
diff --git a/src/UI/Fl_EQGraph.cpp b/src/UI/Fl_EQGraph.cpp
@@ -32,7 +32,7 @@ void Fl_EQGraph::OSC_raw(const char *msg)
samplerate = rtosc_argument(msg, 0).f;
} else {
memcpy(dem, rtosc_argument(msg, 0).b.data, sizeof(dem));
- memcpy(num, rtosc_argument(msg, 1).b.data, sizeof(dem));
+ memcpy(num, rtosc_argument(msg, 1).b.data, sizeof(num));
redraw();
}
}
@@ -141,16 +141,24 @@ void Fl_EQGraph::draw(void)
double Fl_EQGraph::getresponse(int maxy,float freq) const
{
const float angle = 2*PI*freq/samplerate;
- std::complex<float> num_res = 0;
- std::complex<float> dem_res = 0;
+ float mag = 1;
+ //std::complex<float> num_res = 0;
+ //std::complex<float> dem_res = 0;
- for(int i = 0; i < MAX_EQ_BANDS*MAX_FILTER_STAGES*2+1; ++i) {
- num_res += FFTpolar<float>(num[i], i*angle);
- dem_res += FFTpolar<float>(dem[i], i*angle);
+ for(int i = 0; i < MAX_EQ_BANDS*MAX_FILTER_STAGES; ++i) {
+ if(num[3*i] == 0)
+ break;
+ std::complex<float> num_res= 0;
+ std::complex<float> dem_res= 0;
+ for(int j=0; j<3; ++j) {
+ num_res += FFTpolar<float>(num[3*i+j], j*angle);
+ dem_res += FFTpolar<float>(dem[3*i+j], j*angle);
+ }
+ mag *= abs(num_res/dem_res);
}
- float dbresp=20*log(abs(num_res/dem_res))/log(10);
+ float dbresp=20*log(mag)/log(10);
//rescale
return (int) ((dbresp/MAX_DB+1.0)*maxy/2.0);
